GB2477860A

GB2477860A - Microprocessor based control system for use with central heating and hot water applications

Info

Publication number: GB2477860A
Application number: GB1102419A
Authority: GB
Inventors: David Gordon Mckiddie; Alexander Barnie; Gordon Barnie; William Sloan Richmond
Original assignee: SERVICERIGHT LLP
Current assignee: SERVICERIGHT LLP
Priority date: 2010-02-11
Filing date: 2011-02-11
Publication date: 2011-08-17
Also published as: GB201102419D0; GB201002311D0

Abstract

The control system comprises a controller 812 having a microprocessor. The controller is configured to receive at least one input signal from at least one sensor 818 and the microprocessor is responsive to the at least one input signal to provide at least one control signal to control operation of at least one of a boiler 804, circulation pump 803, or valve 810 in dependence on the at least one input signal. The system may include a programmable time controller 801 that activates the boiler during a given time span. The at least one sensor may be a thermostat measuring temperature in a room having a radiator 807, such that the controller may override an activation signal sent by the time controller if the temperature within the room is already above a required threshold. The at least one input signal may be transmitted wirelessly. The system may include user operable switches, such as dil switches, and be retro-fitted to an existing central heating or hot water system, wherein the user may input a configuration of the central heating or hot water system using the dil switches. A method of installing a control system for a heating system, and a method of controlling a heating system are also claimed.

Description

Control system and method

Field of the invention

This invention relates to controllers or control systems, for example controllers or control systems for domestic central heating systems, and to methods of installation or operation of heating systems.

Background to the invention

Research, commissioned by two government funded organisations (Defra and the Energy Saving Trust), identified that twenty-five percent of existing dwellings within the UK have an energy inefficient central heating control system. The research also identified that 50% of the remaining energy efficient domestic central heating control systems were being used inefficiently because building users found the control devices too difficult or complicated to understand, It can be assumed that similar control inefficiencies can also be found in similar sized properties and control systems within the commercial sector, for example boarding houses, office accommodation, dental surgeries, clinics.

To save heating fuel the heating system source of heat (for example the boiler) should only burn fuel when the space and hot water temperatures are below the required level at the time during which the room and hot water temperatures are required and not before. Whilst there are six commonly used industry and nationally recognised and accepted energy efficient electrical control systems for gas or oil fuelled conventional domestic central heating systems (for example central heating systems with water filled radiators) that achieve this control philosophy there are a plethora of existing systems that have been, and are being installed, which fail to do this. Changes to UK Building regulations were made in 2005 to prevent/limit such energy control inefficiencies occurring. These building regulation changes have achieved an element of success, particularly where new build properties are concerned, but the industry recognises that such energy inefficient control system installation practices are still being practised.

There are a number of reasons that may be responsible for this: the capital cost of the additional controls required; the technical complexity of the control systems, the time taken to install these systems and the disruption associated with potential wiring and/or pipework alterations to an existing system to facilitate the installation of one of the six industry recognised and accepted energy efficient conventional central heating control systems when converting an energy inefficient central heating control system to an energy efficient central heating control system. These energy efficient central heating control systems are referred to within the heating and electrical installation industry as the "C-Plan", the "C-Plan Plus", the "S-Plan, the "S-Plan Plus", the "W-Plan" and "Y-Plan" systems. The W-Plan being the forerunner to the Y-Plan system and not commonly used today.

Each of the aforementioned energy efficient central heating control systems are different. They all have individual plumbing and electrical wiring requirements. Some are more energy efficient than others and some provide greater control flexibility.

The known energy efficient central heating control systems mentioned above each includes a programmable controller that operates as a time switch to switch off and on heating control circuits (generally central heating and domestic hot water circuits) at times desired by the user. Each system also includes a boiler, a circulation pump and combinations of motorised valves and room and hot water cylinder thermostats. The motorised valves, thermostats, circulation pump and the boiler are wired together via a wiring box. If wiring is connected correctly then the system is operable to provide automatic switching on and off of the boiler and the circulation pump in dependence on room temperatures and hot water temperatures, and the automatic opening and closing of motorised valves to allow selective heating of heating zones in dependence on room temperatures, and the selective heating of water in dependence on hot water cylinder temperatures.

Because the installation of an efficient central heating control system generally requires the installation services of both plumbing and electrical operatives and because of the complex nature of the electrical connections, the variety of specific control devices needed and misidentification of the various interconnections or final connections that are required the installation and subsequent operation of the control system can be subject to error. For example incompatible control equipment is often installed and wiring mistakes often arise. The end result being that whilst the heating system heats what it was installed to heat it does so energy inefficiently. Furthermore subsequent fault identification and rectification by an engineer may be difficult due to the individual tailored nature of the electrical control system, the pipework distribution system and the extent of building finishes and furnishings within the property.

In general, converting an existing energy inefficient central heating control system to an energy efficient central heating control system by the installation of one of the known energy efficient control systems mentioned above requires considerable effort, time and expertise on the pad of the installer. Usually it is necessary to conduct a technical site survey of the existing installation (prior to any workmen attending site) to determine the pipework size and configuration and identify the location, extent and manufacturer range of all the central heating systems electrical powered and control equipment installed as part of the system. It is possible that some of this equipment may be out of sight, hidden under floor boards and/or non compatible with other control equipment to successfully facilitate the energy efficient control improvement. This is particularly true of motorised valves. It is therefore necessary to gain access to this hidden equipment during the technical survey.

It is an aim of the present invention to provide an improved or at least alternative controller, control system or method to improve the energy efficiency of an existing energy inefficient central heating control system.

Summary of the invention

In a first independent aspect of the invention there is provided a control system for a heating system, the heating system comprising a boiler, and/or at least one circulation pump and/or at least one valve, and the control system comprises:-a controller comprising a microprocessor, wherein the controller is configured to receive at least one input signal from at least one sensor and the microprocessor is responsive to the at least one input signal to provide at least one control signal thereby to control operation of the boiler and/or the at least one circulation pump and/or the at least one valve in dependence on the input signals from the at least one sensor.

The system may further comprise a programmable time controller for controlling operation of the boiler. The programmable time controller may be arranged to operate independently of the controller. The controller may be operable to switch the boiler on or off thereby overriding operation of the programmable time controller.

Thus a further controller may be provided in addition to the programmable time S controller. The programmable time controller may be arranged to operate independently of the controller.

By providing such a further controller that includes a microprocessor for controlling operation of components of the system, energy savings can be achieved, for example in the case where an existing heating system is found to have an energy inefficient heating control system. The system can accommodate many differing existing control systems and equipment, and can accommodate the six main energy efficient central heating control systems currently in use (or any other control systems, if desired), and can make the use of these systems even more effective.

By providing such a further controller an energy efficient system can be provided that is quicker, easier and less disruptive to install than converting an existing inefficient heating system to one of the energy efficient central heating control systems using previously known techniques.

The microprocessor may provide a frost protection control procedure. The controFler may be configured to communicated wirelessly and/or via wired connection with other system components.

The at least one valve may comprise at least one motorized control valve, for example a motorized zone control valve.

The controller may be connectable so that in operation control outputs are sent to the boiler and/or the at least one valve to control operation of the boiler and/or the at least one valve.

The controller may comprise output means for providing at least one output signal to the boiler and/or the at least one circulation pump and/or the at least one valve, the at least one output signal being suitable to affect operation of the boiler and/or the at least one circulation pump and/or the at least one valve, for example to switch the boiler and/or the at least one circulation pump and/or the at least one valve on or off.

The at least one output signal may be the at least one control signal from the microprocessor. Alternatively, the output means may be responsive to at the least one control signal to provide the at least one output signal.

The output means may comprise switching means.

The switching means may be operable to connect at least one input or output of at least one of the boiler, the programmable time controller, the at least one circulation pump, the at least one valve, and the at least one sensor to at least one input or output of at least one other of the boiler, the programmable time controller, the at least one circulation pump, the at least one valve, and the at least one sensor.

Alternatively or additionally, the switching means may be operable to connect an output from a signal source, for example a mains signal source, to at least one input of the boiler, the at least one valve, and the circulation pump.

The switching means may be responsive to the at least one control signal from the microprocessor. For example, the switching means may be responsive to the at least one control signal such that the at least one control signal controls which inputs are connected to which outputs.

The switching means may comprise at least one termination block for receiving the ends of wires that in operation are arranged to provide input or output signals to or from the boiler, the programmable time controller, the at least one valve, the at least one circulation pump and/or the at least one sensor. The wires may be physically connected to the boiler, the programmable time controller, the at least one circulation pump, the at least one valve, and/or the at least one sensor, and/or may be connected to wireless communication means configured to transmit in operation input or output signals to or from the boiler, the programmable time controller, the at least one circulation pump, the at least one valve, and/or the at least one sensor.

The switching means may be arranged to operate to connect different ones of the ends of the wires connected to the termination block in response to the control output signals.

S The switching means may comprise at least one triac switch operable to be responsive to the at least one control signal from the microprocessor.

The controller may comprise a memory for storing at least one control routine. The controller may be operable to perform a selected one of a plurality of control routines.

Each control routine may determine respective output signals provided by the controller and/or a dependency of the output signals on the input signals.

The controller may comprise input means for receiving user input, and the controller may be configured to operate in dependence on the user input. The controller may be configured to select a control routine in dependence on the user input and/or to select the output control signals in dependence on the user input.

The input means may comprise a plurality of user-operable switches, for example dil switches, for selecting a configuration of the heating system.

The user input may be representative of a configuration of the heating system. The user input means may be arranged to provide for the selection of one of a predetermined plurality of heating system configurations. The predetermined plurality of heating system configurations may comprise at least two, or each, of the "C-Plan", the C-Plan Plus", the "S-Plan, the "S-Plan Plus", the W-Plan" and "Y-Plan" configurations. Alternatively or additionally, each of the predetermined plurality of heating system configurations may comprise a configuration of a pipework distribution system and/or a type of water circulation.

The user input may be representative of a selection of frost protection and/or a selected level of frost protection.

The controller may be configured to control the heating of a plurality of heating zones.

The controller may be configured to control the heating of each heating zone independently. The controller may comprise means for setting the timing of heating of each heating zone independently.

The controller may be configured to control the heating of a heating zone, and the S control system may further comprise an auxiliary controller that is operable to receive inputs from temperature sensors in a further heating zone. The controller may comprise communication means for receiving signals from and/or transmitting signals to the auxiliary controller. The controller may be operable to control operation of the boiler and/or at least one further valve to control heating of the further heating zone, for example in dependence on signals received from the auxiliary controller.

The controller may provide a frost protection control procedure, and the controller may be operable to switch the boiler on in accordance with the frost protection control procedure thereby overriding operation of the programmable time controller.

The controller may provide a frost protection control procedure that determines whether to switch the boiler on in dependence on an input signal received from a room thermostat, and the controller may also control operation of the system to maintain a desired temperature of the room during normal operation based upon input signals received from the same thermostat.

The controller may provide a plurality of frost protection control procedures, each frost protection control procedure determining whether to switch the boiler on in dependence on an input signal received from a different temperature sensor.

Each frost protection control procedure may be for providing frost protection for a different room or zone. One of the frost protection control procedures may be for providing frost protection for a zone where the boiler is located, and at least one other frost protection control procedure may be for providing frost protection for at least one further, different zone. The frost protection control procedure for the zone where the boiler is located may comprise switching the boiler on without operating a circulation pump or valve that provides heating to the at least one further zone.

The controller may comprise monitoring means for monitoring the status of at least one of the boiler, the programmable time controller, the at least one circulation pump, the at least one valve, and the at least one sensor and/or for providing at least one status signal representative of the status of at least one of the boiler, the programmable time controller, the at least one circulation pump, the at least one valve and/or representative of the output from the at least one sensor and/or representative of S whether or not the control system is heating a heating zone or hot water.

That feature is particularly important and so in another independent aspeot of the invention there is provided a control system for a heating system, the heating system comprising a boiler, a programmable time controller for controlling operation of the boiler, and/or at least one circulation pump and/or at least one valve, and the control system comprises:-monitoring means for monitoring the status of at least one of the boiler, the programmable time controller, the at least one circulation pump, the at least one valve, and the at least one sensor and/or for providing at least one status signal representative of the status of at least one of the boiler, the programmable time controller, the at least one circulation pump, the at least one valve and/or representative of the output from the at least one sensor and/or representative of whether or not the control system is heating a heating zone or hot water.

The system may further comprise output means for providing output to a user in response to the at least one status signal.

The output means may comprise display means, for example, at least one LED or other light.

Thus, an awareness of energy consumption and/or system usage can be provided to a user.

The output means may be configured to convey to a user that a heating system storage tank requires refilling, and/or that carbon monoxide has been detected and/or that the boiler has been switched off due to safety concerns.

The at least one sensor may comprise at least one temperature sensor, for example at least one thermostat.

Alternatively or additionally, the at least one sensor may comprise a carbon monoxide sensor and/or a fuel level sensor and/or a frost protection sensor.

That feature is particularly important and so in a further independent aspect of the invention there is provided a control system for a heating system, the heating system comprising a boiler, and/or at least one circulation pump and/or at least one valve, and the control system comprising:-a controller comprising a microprocessor, wherein the controller is configured to receive input signals from at least one carbon monoxide sensor and/or fuel level sensor and/or frost protection sensor and the microprocessor is configured to provide control output signals in dependence on the input signals thereby to control operation of the boiler and/or the at least one circulation pump and/or the at least one valve.

In another independent aspect of the invention there is provided a controller for a heating system, the controller comprising a microprocessor and being configured to receive at least one input signal from at least one sensor, wherein the microprocessor is configured to provide at least one control signal thereby to control operation of a boiler and/or at least one valve and/or at least one circulation pump in dependence on the at least one input signal from the at least one sensor.

In another independent aspect of the invention there is provided a method of installing a control system for a heating system, the heating system comprising a boiler, a programmable time controller for controlling operation of the boiler, and/or at least one circulation pump and/or at least one valve, and the method comprising:-, providing a controller comprising a microprocessor; and arranging the controller to receive at least one input signal from at least one sensor, wherein the microprocessor is configured to provide at least one control signal thereby to control operation of the boiler and/or the and/or the circulation pump and/or at least one valve in dependence on the at least one input signal from the at least one sensor.

The method may comprise a method of adapting an existing heating system. The method may comprise replacing a wiring unit of the existing heating system with the or a controller. The method may comprise installing the at least one sensor.

In another independent aspect of the invention there is provided a method of controlling a heating system, the heating system comprising a boiler, a programmable time controller for controlling operation of the boiler, and/or at least one valve, and the method comprising:-receiving at least one input signal from at least one sensor and s providing at least one control signal thereby to control operation of the boiler and/or the circulation pump and/or the at least one valve in dependence on the input signals from the at least one sensor. The at least one valve may comprise at least one motorized control valve, for example a motorized zone control valve.

In another independent aspect of the invention there is provided a controller for a water filled domestic heating system, the heating system comprising a gas or oil fired boiler, a programmable time controller, a circulating pump, a pipework distribution system and at least a first sensor or sensors responsive to the temperature or conditions affecting the temperature in a zone or zones to be selectively heated wherein the primary controller controls the operation of the boiler in response at least to input(s) received from said first sensor or sensors and programmable time controller via hard wiring and/or compatible radio communication and provide the necessary interconnection there between to facilitate energy efficient control of the boiler, the said primary controller also being capable of communicating by wireless communication to auxiliary zone control units that receive inputs from time controllers and temperature sensors responsive to temperature or conditions affecting the temperature in another heating zone to be controlled by the controller.

The primary controller may comprise switch means to selectively operate or to adapt the control system in cognisance of the configuration of the pipework distribution system and the type of water circulation chosen, for example a combination of gravity and pumped circulation, or fully pumped circulation systems, and the type, if any, of frost protection chosen.

The primary controller may comprise a microprocessor, radio transmitter and receiver unit mounted to a printed circuit board together with a power supply enabling the microprocessor to accept and transmit communication received from hard wired and/or compatible wireless heating control devices of the heating control system and to communicate the appropriate and configurable control options to a combination of triac switching circuits and subsequent termination block to which inputs and outputs are ii received from and to any hard wired heating devices that are part of the system, for example boilers, circulating pumps, thermostats/sensors and motorised valves. The internal conducting and communication paths may be provided on the printed circuit board.

S

The primary controller may comprise a means of conveying to the building user when the boiler is off and the status of the temperature sensors in each of the zones to be heated and, in the case of compatible wireless sensors, when the batteries in the sensors are due to be replaced. The primary controller may also comprise a means of conveying to the building user that the frost protection system has activated and being capable of communicating these status indications to strategically remote status indicators within the same heating control system.

The primary controller may be configured to only accept compatible radio control is devices bonded/registered to the individual primary controller and to allow replacement and/or additional compatible radio control devices to be bonded/registered to it at any subsequent stage.

The controller may incorporate additional means of conveying to the building user when a heating system storage tank is soon requiring refilling and/or means for switching off the heating system boiler when carbon monoxide has been detected within the property and/or conveying to the building user that the heating boiler has been switched off due to safety concerns.

The controller may incorporate an internal/integral temperature sensor to provide an additional means of frost protection for the heating system.

The controller may incorporate integral programmable time control of one or more heating zones of the system.

The controller may be a two zone controller for controlling central heating and hot water zones. Alternatively, the controller may be configured to control one zone or more than two zones. The controller may, for example, not have integral time control. Additional heating control zones can be added to the system by for example use of zone extender units and external time control. An integral frost protection sensor option may be provided. A cylinder thermostat and strap on sensor may be provided -for example to provide temperature control of the domestic hot water contained within a domestic hot water cylinder. A carbon monoxide detector may be provided this detector may work in conjunction with the controller switching OFF the bailer when carbon monoxide is detected. The controller may be configured to accept signals from this detector. A fuel level monitor may be provided -this sensor will be developed to monitor the fuel level of a central heating system external oil or gas fuel storage lank and will work in conjunction with the controller to advise the user that fuel in the storage tank has reached a pre-determined level, for example is about to run out.

There may also be provided an apparatus or method substantially as described herein with reference to the accompanying drawings.

Any feature in one aspect of the invention may be applied to other aspects of the invention, in any appropriate combination. For example, apparatus features may be applied to method features and vice versa.

Detailed description of embodiments

Embodiments of the invention are now described, by way of non-limiting example, and are illustrated in the following figures, in which:-Figure 1 is a schematic diagram of a known central heating system; Figure 2 is a schematic diagram of a known modification to the system of Figure 1; Figure 3 is a schematic diagram of a further modification to the system of Figure 1; Figure 4 is a schematic diagram of a central heating system including a control system according to one embodiment; Figure 5 is a schematic diagram of another known central heating system; Figure 6 is a schematic diagram of a known modification to the system of Figure 5; Figure 7 is a schematic diagram of a further known modification to the system of Figure 5; Figure 8 is a schematic diagram of a central heating system including a control system according to a further embodiment; and Figure 9 is a schematic diagram of a controller according to an embodiment.

Various heating and electrical industry terms used in describing the various embodiments are discussed, before the embodiments themselves are described.

A central heating boiler -this is usually a unit that uses a fuel source to heat water (not boil the water) to a temperature which can be used for heating purposes by radiant and/or convection from a water filled pipework distribution system. A central heating boiler should not boil water -in fact there are usually control and safety thermostats within the boiler unit to prevent such an occurrence. The fuel source may be any suitable power source for example mains gas or electricity.

A radiator -this is usually a unit designed to improve the output efficiency of convected heat from a hot water filled pipework distribution system emanating from the central heating boiler. The radiators are located within areas/spaces of a building to be heated (for example a room). The radiant heat emitted from a radiator is a fraction of the convected heat that emanates from the radiator. Radiators are used to provide space heating.

A central heating programmer/programmable controller/central heating controller -in known systems this is usually a time switch. A wide range and scope of central heating programmers are available. They can vary greatly in design but known controllers usually contain a clock, which by various means provide switched electrical supplies to turn space heating and hot water zones within a central heating system (sometimes separately) automatically ON and OFF when required by the building user. Some time switches have a discreet selector switch allowing the time control to be set to allow either:..

* hot water (NW) only and, I-lW and central heating (CR) o NW only, CH only, or HW and CH Some domestic central heating time switches allow several different ON and OFF times to be set for weekdays, weekends and each day of the week. Some allow holiday periods to be set effectively switching off the ON switching periods for a set number of days. Some have boost ON and OFF manual override buttons, allowing the building user to switch a heating zone ON early for a predetermined set period of time or to switch OFF the heating zone early.

A room thermostat -this is usually a switch that is part of a electrical central heating control circuit which is activated at set predetermined air temperature settings determined and set by the building user to control the temperature in a heated room or zone within the property. Room thermostats are generally, but not exclusively, fixed to the surface of a wall.

A thermostatic radiator valve (TRV) -this may be a non-electrical mechanically operated switch fitted to a radiator which is activated and switches off the hot water supply to the radiator at set predetermined air temperature settings determined and set by the building user to control the temperature in a heated room within a property.

A cylinder thermostat -this is usually a switch that is part of a eLectrical central heating control circuit which is activated at predetermined surface temperature settings of the domestic hot water storage cylinder, determined and set by the building user to control the temperature of the hot water within the hot water storage cylinder. Cylinder thermostats are generally, but not exclusively, strapped to the surface metal of the domestic hot water storage cylinder.

A thermostatic control valve (TCV) -this may be a non-electrical mechanically operated switch that is fitted to the domestic hot water cylinder's pipework distribution system that when activated switches off the hot water supply to the hot water cylinder at a set predetermined surface temperature that is set and determined by the building user to control the temperature of the domestic hot water within the cylinder.

Frost thermostat -this may be a switch that is part of an electrical central heating control circuit which is activated at predetermined "low" air temperature settings determined and set by the building user to control and keep the temperature within the property above a set temperature level to protect the boiler and/or the building fabric against freezing conditions. Frost thermostats are generally fixed to the surface of a wall.

Gravity fed systems -these are usually systems in which the hot water in the domestic HW storage cylinder (heated by the boiler) is circulated through a heating system pipework distribution system by convection currents and gravity. In such systems the hot water may naturally rise to the highest point in the pipework distribution system displacing and pushing the cold water in the system as it rises so as the cold water falls to the bottom of the pipework distribution system (at the boiler) to be heated up again and so forth. Gravity fed systems for central/space heating purposes are not as common as they once were but they can still be found and still have their purpose even S today. Much more common however is the use of gravity for the provision of heating of a domestic hot water cylinder and pumped circulation for the space heating system.

Pumped circulation -this is usually a system in which the hot water (heated by the boiler) is circulated through the heating pipework distribution system for space heating purposes by an electric pump.

Fully pumped system -this is usually a system in which the hot water (heated by the boiler) is circulated through the heating pipework distribution system for both domestic hot water and space heating purposes.

A wiring centre/termination centre -this is usually an electrical joint or junction box.

A motorised valve/motorised zone valve/zone valve (MV) -this may be an electrically operated valve, which allows and prevents the water from flowing within a certain areas of a building's pipework distribution system. There are many types of motorised valves.

Some simply require electrical power to drive" the valve open and then when the electrical power is removed a spring returns the valve to the closed position. Some MVs require electrical power to first open and then to close the valve and other MVs have multiple electrical power supplies driving the valve open or closed or partly open in order that the valve opens, closes or diverts the water within the heating pipework distribution system. Some MVs contain one or more auxiliary electrical switches that mechanically operate and switch electrical power in differing electrical switch circuits as the MV opens, closes or diverts the water within the heating system pipework distribution system.

An auto by-pass valve -this is usually a non electrical pressure valve which progressively opens and allows water to pass through it as the pressure builds up within the pipework distribution system as other valves in other parts of the system close.

Technical surveys -a technical survey in this context is a survey of the existing electrical and mechanical aspects of the central heating system that is carried out in advance of operatives attending site to carry out a conversion of the system. The purpose of the technical survey is to determine the full extent of the mechanical and electrical components of the central heating system in order that a cost effective energy efficient control solution can be identified, and in order that work and equipment can be identified, costed and purchased in advance of the operatives attending site to carry out the conversion.

Figure 1 shows a schematic diagram of a simple, known energy inefficient domestic central heating system. In this example the central heating system comprises pipework distribution circuits for central heating 110 and domestic hot water 111. The central heating time switch 101 controls, via electrical control cables 112 and 113, the timed operation of the heating boiler 104 and the central heating circulation pump 103 and is motorised valve 107. The HW time switch controls the ON, OFF operation of the boiler allowing heated hot water from the boiler to move by convection round the HW pipework distribution pipework 111. The OH time switch controls the ON, OFF operation of the circulation pump 103 and the opening of the MV 107 to allow the water to circulate round the space heating pipework distribution system 110 from the boiler 104. In this example the central heating time switch can only operate provided the hot water time switch is in the ON position first. Switching the HW time switch off also simultaneously switches the central heating time switch off. The temperature of the HW in the domestic hot water storage cylinder 102 is controlled by the thermostatic control valve 108. The temperatures of the rooms in the property are controlled by the thermostatic radiator valves 106 which are connected at each radiator 105 throughout the dwelling. In this example the boiler will continue to burn fuel when all the rooms in the property and the temperature of the domestic hot water have reached their desired set comfort temperatures for the duration of the set ON period of the time switch(es) as there is no means of communication to the boiler that the set temperature settings of either the rooms and the hot water have been achieved and therefore there is no means of instructing the boiler to switch OFF to save fuel when this occurs.

Frost protection is usually a system extra and can be added to figure 1 to protect the boiler only by installing a frost thermostat 114 and control cable 115 subsequently interlinking the frost thermostat to time switch 101. The frost thermostat effectively overrides the HW time switch when the air temperature falls to a preset low level temperature level and switches the boiler 104 ON until such times as the frost thermostat senses that the air temperature has risen above the preset temperature level.

Figure 2 shows a schematic diagram of a known control solution for the system detailed in figure 1 which prevents the boiler from continually burning fuel when the temperature of the rooms and the domestic hot water have reached the desired set comfort temperatures during the set ON period of the time switch(es). This control solution is referred to as a C-Plan Plus system.

Before this control solution can be implemented it is necessary to conduct a technical site survey of the existing installation to determine the pipework size and configuration and identify the location, extent and manufacturer range of all the central heating systems electrical powered and control equipment installed as part of the system. It is possible that some of this equipment may be out of sight, hidden under floor boards and/or non compatible with other control equipment to successfully facilitate the energy efficient control improvement. This is particularly true of motorised valves. It is therefore necessary to gain access to this hidden equipment during the technical survey. The findings of the technical survey allow a cost effective control solution to be determined and subsequently adopted/installed following the identification and purchase of replacement and/or additional control equipment necessary to satisfactory complete the energy efficient control solution.

In the example of figure 2, it is necessary to install a motorised valve 208 in the domestic hot water distribution system pipework 211, a cylinder thermostat 214, a room thermostat 213 and a wiring centre 212. The central heating system is required to be drained down and/or a section of pipework frozen to facilitate the removal of thermostatic control valve 108 in figure 1 with a replacement motorised valve 208 in figure 2. The pipework diameter needs to be known before MV 208 can be purchased.

To prevent the boiler from staying ON and wasting fuel when the domestic hot water and room temperatures are satisfied it is important that MV 208 and MV 207 have compatible auxiliary switches contained within them which must also be wired back to the wiring centre 212 via cables 219 and 220. Access has to be provided to facilitate the installation of cabling 220 to the MV 205, cabling 222 to the cylinder thermostat, cabling 221 to the room thermostat 213 and maybe cabling 219 to the central heating MV 207. If the MV 107 in figure 1 is of the wrong type and/or auxiliary switch configuration required for the control figuration in figure 2 then MV 107 in figure 1 would need to be replaced. At best this would require the purchase and replacement of the S electrical powered and auxiliary switch section of MV 207.

Furthermore in figure 2, the previous wiring 112 and 113 referred to in figure 1 from the NW and CH time switch 101 to the central heating boiler 104 and the MV 107 and circulation pump 103 has to be broken into and rerouted in figure 2 to the wiring centre 212. The wiring from the HW and OH time switch 201 in figure 2 is referred to as 215 and 216 respectively. In figure 2 cabling 218 from boiler 204 and cabling 217 from the circulation pump 203 is also re-routed or installed to the wiring centre 212.

The wiring centre 212 typically consists of a length or strip of screw down terminal blocks concealed within a plastic enclosure. The installing engineer manually makes all of the appropriate interconnections from and between the various control system equipment by terminating individual cable cores from each device and any necessary cable links into pre-chosen termination blocks of the connector strip. In figure 2, once the room thermostat 213 receives an electrical supply from time switch 201 it controls the boiler 204, the circulation pump 203 and MV 207 effectively switching the boiler OFF during the time switch ON period when the room temperature has reached the desired set point. Similarly the cylinder thermostat 214 controls the boiler 204 and MV 208 effectively switching the boiler OFF during the time switch ON period when the HW temperature has reached the desired set point. The auxiliary switches in MV 207 and MV 208 are interlinked within the wiring centre 212 to prevent the valves from opening and/or the pump from operating inadvertently when the other zone is calling for heat.

This system allows the HW and the CH to be switched ON and OFF independently of each other. If the time switch in figure 1 has a discreet selector switch to accommodate this mode of operation then to accommodate this, the switch requires to be set to the alternate position.

As identified above frost protection is usually a system extra and can be added in figure 2 to protect the boiler only and/or the property by installing a frost thermostat 223 and control cable 224 which interlinks the frost thermostat to the wiring centre 212. The frost thermostat effectively overrides either the NW or OH time switch when the air temperature falls to a preset low level temperature level and switches the boiler 204 ON in the case of boiler protection only or switches the boiler 204 and circulation pump 203 ON and opens MV 207 when property frost protection is to be provided until such times as the frost thermostat senses that the air temperature has risen above the preset temperature level.

The complete manual conversion of the heating system energy efficient control system in figure 2 and described above is both time consuming for the installing contractor and installation engineer because of the complex nature of the electrical connections, the specific control devices needed and due to the individual tailored nature of the pipewcrk distribution system and the extent of building finishes and furnishings within the property.

Figure 3 shows a schematic diagram of an existing conventional wireless control solution for the system detailed in figure 1 which prevents the boiler from continually burning fuel when the temperature of the rooms and the domestic hot water have reached the desired set comfort temperatures during the set ON period of the time switch(es). This control solution is still referred to as a C-Plan Plus system.

As is the case with the control system detailed in figure 2, before this control solution can take place it is necessary to conduct a technical site survey of the existing installation to determine the pipework size and configuration and identify the location, extent and manufacturer range of all the central heating systems electrical powered and control equipment installed as part of the system. It is possible that some of this equipment may be out of sight, hidden under floor boards and/or non compatible with other control equipment to successfully facilitate the energy efficient control improvement. This is particularly true of motorised valves. It is therefore necessary to gain access to this hidden equipment during the technical survey. The findings of the technical survey allow a cost effective control solution to be determined and subsequently adopted/installed following the identification and purchase of replacement and/or additional control equipment necessary to satisfactory complete the energy efficient control solution.

In the example of figure 3, it is necessary to install a motorised valve 308 in the domestic hot water distribution system pipework 311, a cylinder thermostat 314, a room thermostat 313 and a wiring centre 312. The central heating system is required to be drained down and/or a section of pipework frozen to facilitate the removal of thermostatic control valve 108 in figure 1 with a replacement motorised valve 308 in figure 3. The pipework diameter needs to be known before MV 308 can be purchased.

S To prevent the boiler from staying ON and wasting fuel when the domestic hot water and room temperatures are satisfied it is important that MV 308 and MV 307 have compatible auxiliary switches contained within them which must also be wired back to the wiring centre 312 via cables 319 and 320. Access has to be provided to facilitate the installation of cabling 320 to the MV 308 and, in some cases, cabling 319 to the central heating MV 307. If the MV 107 in figure 1 is of the wrong type and/or auxiliary switch configuration that is required for the control figuration in figure 3 then MV 107 in figure 1 would need to be replaced. At best this would require the purchase and replacement of the electrical powered and auxiliary switch section of MV 307. There is no requirement to install cabling 222 to the cylinder thermostat or cabling 221 to the room thermostat 213 referred to in figure 2 as the room and cylinder thermostats in figure 3 transmit control signals to receiver unit 324 by radio transmission. It is necessary however to interlink with control cable 321 the receiver unit 324 with the wiring centre 312 effective creating the same control cabling circuit from a shorter location then would otherwise have occurred.

Furthermore in figure 3, the previous wiring 112 and 113 referred to in figure 1 from the HW and OH time switch 101 to the central heating boiler 104 and the MV 107 and circulation pump 103 has to be broken into and rerouted in figure 3 to the wiring centre 312 and receiver unit 324. The wiring from the HW and OH time switch 301 in figure 3 referred to as 315 and 316 respectively, in figure 3 cabling 318 from boiler 304 and cabling 317 from the circulation pump 303 is also re-routed or installed to the wiring centre 312.

As was the case in figure 2, the wiring centre 312 in figure 3 typically consists of a length or strip of screw down terminal blocks concealed within a plastic enclosure. The installing engineer manually makes all of the appropriate interconnections from and between the various control system equipment by terminating individual cable cores from each device and any necessary cable links into pre chosen termination blocks of the connector strip. In figure 3, once the room thermostat 313 receives a signal from time switch 301 via receiver unit 324 it controls the boiler 304, the circulation pump 303 and MV 307 effectively switching the boiler OFF during the time switch ON period when the room temperature has reached the desired set point. Similarly the cylinder thermostat 314 controls the boiler 304 and MV 308 effectively switching the boiler OFF during the time switch ON period when the HW temperature has reached the desired set point. The auxiliary switches in MV 307 and MV 308 are interlinked within the wiring centre 312 to prevent the valves from opening and/or the pump from operating inadvertently when the other zone is calling for heat. This system allows the HW and the CH to be switched ON and OFF independently of each other. If the time switch in figure 1 has a discreet selector switch to accommodate this mode of operation then to accommodate this, the switch is required to be set to the alternate position.

As identified above frost protection is usually a system extra and can be added in figure 3 to protect the boiler and/or the property by installing a frost thermostat 322 and control cable 323 which interlinks the frost thermostat to the wiring centre 312. The frost thermostat effectively overrides either the HW or CH time switch when the air temperature falls to a preset low level temperature level and switches the boiler 304 ON in the case of boiler protection only or switches the boiler 304 and circulation pump 303 ON and opens MV 307 when property frost protection is to be provided, until such times as the frost thermostat senses that the air temperature has risen above the preset temperature level.

The provision of system status indicators on the time switch 101, 201 and 301 in figures 1, 2 and 3 the wiring centre 212 and 312 in figures 2 and 3 and the wireless receiver unit 324 in figure 3 is restricted and typically limited to visual indication by power ON indication lamps that illuminate when a main source of electrical power is available to the control system and/or the time switch has provided electrical power to the HW or CH zone control circuitry.

The complete manual conversion of the central heating system energy efficient control system in figure 3 and described above is still time consuming for the installing contractor and installation engineer because of the complex nature of the electrical connections, the specific control devices needed and due to the individual tailored nature of the pipework distribution system and the extent of building finishes and furnishings within the property.

Figure 4 shows a schematic diagram of a wireless control solution according to one embodiment for the system detailed in figure 1 that prevents the boiler from continually burning fuel when the temperature of the rooms and the domestic hot water have reached the desired set comfort temperatures during the set ON period of the time S switch(es).

Unlike the control solutions described in figures 2 and 3 it is not necessary to conduct a technical site survey of the existing installation before operatives attend site to install the energy efficient control solution detailed in figure 4.

In the embodiment of figure 4, it is necessary to install a wireless cylinder thermostat 414 and a wireless room thermostat 413. The previous wiring 112 and 113 referred to in figure 1 from the HW and OH time switch 101 to the central heating boiler 104 and the MV 107 and circulation pump 103 has to be broken into and rerouted in figure 4 to the controller 412. The wiring from the HW and OH time switch 401 in figure 4 referred to as 415 and 416 respectively and cabling 419 from MV 407, cabling 418 from boiler 404 and cabling 417 from the circulation pump 403 are also re-routed or installed to the controller 412.

The installing engineer manually connects cable cores from the various control system equipment into pre-identified termination blocks within the controller 412. As described in more detail below, in relation to Figure 9, the controller 412 includes a microprocessor that determines what output signals are provided by the controller in response to input signals from the thermostats or other sensors. The installing engineer determines what type the heating system is (for example, "C-Plan", C-Plan Plus", "S-Plan, S-Plan Plus", "W-Plan" or Y-Plan") and manually sets switches on the controller 412 to select the type of the system and other parameters, for example whether the system is fully pumped or gravity fed. The cable cores from different components of the system (for example boiler, circulation pump, thermostat or other sensor, motorised valves) are inserted into respective pre-determined ones of the termination blocks. The microprocessor selects a control routine in dependence on the selected type of the heating system, and in operation provides appropriate outputs to provide energy efficient control of the heating system in response to the inputs received from the thermostats or other sensors.

In figure 4, once the room thermostat 413 receives a signal from controller 412 it controls the boiler 404, the circulation pump 403 and MV 407 effectively switching the boiler OFF during the time switch ON period when the room temperature has reached the desired set point. Similarly the cylinder thermostat 414 controls the boiler 404 effectively switching the boiler OFF during the time switch ON period when the HW temperature has reached the desired set point. Thus, the controller 412 can override operation of the programmable time controller which would, in the absence of the controller, maintain the boiler ON even though the room or cylinder temperature had reached a desired set point. Thus, the controller can enable a reduction in energy consumption.

The electronic switching circuitry within the controller 412 prevents MV 407 from opening and/or the circulating pump 403 from operating inadvertently when the other heating zone is calling for heat and the boiler 404 is ON. This system allows the HW and the OH to be switched ON and OFF independently of each other. If the time switch in figure 1 has a discreet selector switch to accommodate this mode of operation then to accommodate this, the switch requires to be set to the alternate position.

In figure 4, frost protection is provided integrally within the room thermostat 413. The room thermostat effectively sends a signal to the controller to override both the HW and OH time switches 401 when the room thermostat senses that the air temperature has fallen to a preset low level temperature level and subsequently switches the boiler 404 and circulation pump 403 ON and opens MV 407 until such times as the cylinder thermostat 414 and room thermostat 413 sense that the hot water temperature within the hot water storage cylinder 402 and the room air temperature has reached the preset temperature levels defined by the building user where after the boiler 404 and circulation pump 403 switch OFF and MV 407 closes.

The controller in figure 4 is provided with visual system status indicators that illuminate when each heating zone is activated ON by the time controller and also provides a visual indication of the operational status of the control cylinder thermostat 414 and room thermostat 413 which illuminate when the set point temperatures of the thermostats have still to be achieved.

Figure 5 shows a schematic diagram of a more complex energy inefficient domestic central heating system. In this example the central heating system comprises pipework distribution circuits for two central heating 514 and 515 zones and a domestic hot water pipework distribution circuit 513. The central heating time switch 501 controls via electrical control cables 517, 518 and 519, the timed operation of the heating boiler 504 and the central heating circulation pump 503 and motorised valves 509 and 510. The HW time switch controls the ON, OFF operation of the boiler allowing heated hot water from the boiler 504 to move by convection round the HW pipework distribution pipework 513. The CHI time switch controls the ON, OFF operation of the circulation pump 503 and the opening of the MV 510 to allow the water to circulate round the space heating pipework distribution system 514 from the boiler 504. The CH2 time switch controls the ON, OFF operation of the circulation pump 503 and the opening of the MV 509 to allow the water to circulate round the space heating pipework distribution system 515 from the boiler 504. In this example the central heating time switches can only operate provided the hot water time switch is in the ON position first.

Switching the HW time switch off prevents the heating of the central heating pipework distribution circuits 514 and 515 and may also simultaneously switch the central heating time switch OFF. The circulation pump 503 is ON and MV 510 is open when the central heating time switch CH1 is ON. The CH2 time switch only opens MV 509. In this instance the Cl-Il time switch must be ON to allow hot water to flow through the central heating pipework distribution system 515. The temperature of the HW in the domestic hot water storage cylinder 502 is controlled by the thermostatic control valve 511. The joint box 512 is utilised to make the physical cable core control terminations from the circulation pump 503, the MVs 509 and 510 and the CH1 and CH2 time switches in time switch 501 into various connector blocks housed within the plastic enclosure of the joint box. The temperatures of the rooms in each heated zone of the property are controlled by the thermostatic radiator valves 506 and 508 which are connected at each radiator 505 and 507 throughout the dwelling. In this example the boiler will continue to burn fuel when all the rooms in the property and the temperature of the domestic hot water have reached their desired set comfort temperatures for the duration of the set ON period of the time switch(es) as there is no means of communication to the boiler that the set temperature settings of within the rooms and the hot water cylinder has been achieved and therefore there is no means of instructing the boiler to switch OFF to save fuel when this occurs.

Frost protection is usually a system extra and can be added to the system of figure 5 to protect the boiler only by installing a frost thermostat 523 and control cable 524 subsequently interlinking the frost thermostat to time switch 1. The frost thermostat effectively overrides the HW time switch when the air temperature falls to a preset low level temperature level and switches the boiler 504 ON until such times as the frost thermostat senses that the air temperature has risen above the preset temperature level.

Figure 6 shows a schematic diagram of an existing conventional control solution for the system detailed in figure 5 which prevents the boiler from continually burning fuel when the temperature of the rooms and the domestic hot water have reached the desired set comfort temperatures during the set ON period of the time switch(es). This control solution is referred to as an S-Plan Plus system.

Before this control solution can be implemented it is necessary to conduct a technical site survey of the existing installation to determine the pipework size and configuration and identify the location, extent and manufacturer range of all of the central heating systems electrical powered and control equipment installed as part of the system. It is possible that some of this equipment may be out of sight, hidden under floor boards and/or non compatible with other control equipment required to successfully facilitate an energy efficient control improvement. This is particularly true of motorised valves. It is therefore necessary to gain access to this hidden equipment during the technical survey. The findings of the technical survey allow a cost effective control solution to be determined and subsequently adopted/installed following the identification and purchase of replacement and/or additional control equipment necessary to satisfactory complete the energy efficient control solution.

In the example of figure 6, it is necessary to install a motorised valve 611 in the domestic hot water distribution system pipework 613, a cylinder thermostat 617, two room thermostats 618 and 619 and a wiring centre 612. The central heating system is required to be drained down to facilitate the removal of thermostatic control valve 511 in figure 5 with a replacement motorised valve 611 in figure 6 and the change of central heating pipework distribution system configuration to accommodate a fully pumped system. The pipework diameter needs to be known before MV 611 can be purchased.

To prevent the boiler from staying ON and wasting fuel when the domestic hot water and room temperatures are satisfied it is important that MV 611, MV 609 and MV 610 have compatible auxiliary switches contained within them which must also be wired back to the wiring centre 612 via cables 624, 625 and 626. Access has to be provided to facilitate the installation of cabling 626 to the MV 611, cabling 628 to the cylinder thermostat, cabling 629 and 630 to the room thermostats 618 and 619 and, in some cases, cabling 621 and 622 to the central heating MV 609 and MV61O. If MV 509 and MV 510 in figure 5 are of the wrong type and/or auxiliary switch configuration that is required for the control configuration in figure 6 then MV 509 and MV 510 in figure 5 would need to be replaced. This may require the purchase and replacement of the electrical powered and auxiliary switch section of MV 609 and MV 610.

Furthermore in figure 6, the previous wiring 517, 518 and 519 referred to in figure 5 from the HW, CH1 and CH2 time switch 501 to the central heating boiler 504 and MV 509 and MV 510 and circulation pump 503 has to be broken into and rerouted in figure 6 to the wiring centre 612. The wiring from the HW and CH time switch 601 in figure 6 referred to as 620, 621 and 622 respectively and cabling 627 from boiler 604 and cabling 623 from the circulation pump 603 is also re-routed or installed to the wiring centre 612.

As previously identified the wiring centre 612 typically consists of a length or strip of screw down terminal blocks concealed within a plastic enclosure. The installing engineer manually makes all of the appropriate interconnections from and between the various control system equipment by terminating individual cable cores from each device and any necessary cable links into pre chosen termination blocks of the connector strip. In figure 6, once a room thermostat 618 and/or 619 receives an electrical supply from time CH1 or CH2 time switch in time switch 601 the zone thermostat controls the boiler 604, the circulation pump 603 and the appropriate zone MV 609 or MV 610 effectively switching the boiler OFF during the time switch ON period when the room temperature has reached the desired set point. Similarly the cylinder thermostat 617 controls the boiler 604, the circulation pump 603 and MV 611 effectively switching the boiler and pump OFF and closing the valve during the time switch ON period when the HW temperature has reached the desired set point. The auxiliary switches in MV 609, MV 610 and MV 611 are interlinked within the wiring centre 612 to prevent the valves from opening and/or the pump and/or boiler from operating inadvertently when one of the other zones are calling for heat. This system allows the HW and CH1 and CH2 to be switched ON and OFF independently of each other. If the time switch in figure 5 has a discreet selector switch to accommodate this mode of operation then to accommodate this, the switch requires to be set to the alternate position.

S

As identified above frost protection is usually a system extra and can be added in figure 6 to protect the boiler only and/or the property by installing a frost thermostat 631 and control cable 632 which interlinks the frost thermostat to the wiring centre 612. The frost thermostat effectively overrides either the HW or OH time switch circuits when the air temperature falls to a preset low level temperature level and switches the boiler 604 and circulation pump 603 ON and opens either MV 609, MV 610 or MV 611 in the zone being protected and where the frost thermostat is located until such times as the frost thermostat senses that the air temperature has risen above the preset temperature level. If it is a requirement to provide frost protection for all the heating zones in the system then additional frost thermostats must be installed and hard wired back to the control centre 612 to facilitate the appropriate interconnections.

The complete manual conversion of the heating system energy efficient control system in figure 6 and described above is time consuming for both the installing contractor and installation engineer because of the complex nature of the electrical connections, the specific control devices needed and due to the individual tailored nature of the pipework distribution system and the extent of building finishes and furnishings within the property.

Figure 7 shows a schematic diagram of an existing conventional wireless control solution for the system detailed in figure 5 which prevents the boiler from continually burning fuel when the temperature of the rooms and the domestic hot water have reached the desired set comfort temperatures during the set ON period of the time switch(es). This control solution is still referred to as an S-Plan Plus system.

Before the control system of Figure 7 can be implemented it is still necessary to conduct a technical site survey of the existing installation to determine the pipework size and configuration and identify the location, extent and manufacturer range of all of the central heating systems electrical powered and control equipment installed as part of the system. It is possible that some of this equipment may be out of sight, hidden under floor boards and/or non compatible with other control equipment required to successfully facilitate an energy efficient control improvement. This is particularly true of motorised valves. It is therefore necessary to gain access to this hidden equipment during the technical survey. The findings of the technical survey allow a cost effective S control solution to be determined and subsequently adopted/installed following the identification and purchase of replacement and/or additional control equipment necessary to satisfactory complete the energy efficient control solution.

In the example of figure 7, it is necessary to install a motorised valve 711 in the domestic hot water distribution system pipework 713, a cylinder thermostat 717, two room thermostats 718 and 719 and a wiring centre 712. The central heating system is required to be drained down to facilitate the removal of thermostatic control valve 511 in figure 5 with a replacement motorised valve 711 in figure 7 and the change of central heating pipework distribution system configuration to a accommodate a fully pumped system. The pipework diameter needs to be known before MV 711 can be purchased.

To prevent the boiler from staying ON and wasting fuel when the domestic hot water and room temperatures are satisfied it is important that MV 711, MV 709 and MV 710 have compatible auxiliary switches contained within them which must also be wired back to the wiring centre 712 via cables 725, 726 and 728. Access has to be provided to facilitate the installation of cabling 728 to the MV 711 and, in some cases, cabling 725 and 726 to the central heating MV 709 and MV 710. If MV 509 and MV 510 in figure 5 are of the wrong type and/or auxiliary switch configuration that is required for the control configuration in figure 7 then MV 509 and MV 510 in figure 5 would need to be replaced. At best this would require the purchase and replacement of the electrical powered and auxiliary switch section of MV 709 and MV 710. There is no requirement to install cabling 628 to the cylinder thermostat 617 or cabling 629 and 630 to the room thermostat 68 and 619 referred to in figure 6 as the room and cylinder thermostats in figure 7 transmit control signals to receiver unit 720 by radio transmission. It is necessary however to interlink with control cable 729 the receiver unit 720 with the wiring centre 712 effective creating the same control cabling circuit from a shorter location then would otherwise have been necessary.

Furthermore in figure 7, the previous wiring 517, 518 and 519 referred to in figure 5 from the HW, CH1 and CH2 time switch 501 to the central heating boiler 504 and MV 509 and MV 510 and circulation pump 503 has to be broken into and rerouted in figure 7 to the wiring centre 712 the wiring from the HW and CH time switch 701 in figure 7 referred to as 721, 722 and 723 respectively. In figure 7 cabling 727 from boiler 704 and cabling 724 from the circulation pump 703 is also re-routed or installed to the wiring centre 712.

As in figures 6 and 7 the wiring centre 612 and 712 typically consists of a length or strip of screw down terminal blocks concealed within a plastic enclosure. The installing engineer manually makes all of the appropriate interconnections from and between the various control system equipment by terminating individual cable cores from each device and any necessary cable links into pre-chosen termination blocks of the connector strip. In figure 7, once room thermostats 718 and/or 719 receives an electrical supply from time CH1 or CH2 time switch in time switch 701 the zone room thermostat controls the boiler 704, the circulation pump 703 and the appropriate zone MV 709 or MV 710 effectively switching the boiler OFF during the time switch ON period when the room temperature has reached the desired set point. Similarly the cylinder thermostat 717 controls the boiler 704 and MV 711 effectively switching the boiler OFF during the time switch ON period when the HW temperature has reached the desired set point. The auxiliary switches in MV 709, MV 710 and MV 711 are interlinked within the wiring centre 712 to prevent the valves from opening and/or the pump and/or boiler from operating inadvertently when one of the other zones are calling for heat. This system allows the HW and CH1 and CH2 to be switched ON and OFF independently of each other. If the time switch in figure 5 has a discreet selector switch to accommodate this mode of operation then to accommodate this, the switch requires to be set to the alternate position.

As identified above frost protection is usually a system extra and can be added in figure 7 to protect the boiler only and/or the property by installing a frost thermostat 730 and control cable 731 which interlinks the frost thermostat to the wiring centre 712. The frost thermostat effectively overrides either the HW or CH time switch circuits when the air temperature falls to a preset low level temperature level and switches the boiler 704 and circulation pump 703 ON and opens either MV 709, MV 710 or MV 711 in the zone being protected and where the frost thermostat is located until such times as the frost thermostat senses that the air temperature has risen above the preset temperature level. If it is a requirement to provide frost protection for all of the heating zones in the system then additional frost thermostats must be installed and hard wired back to the control centre 712 to facilitate the appropriate interconnections.

The provision of system status indicators on the time switch 501, 601 and 701 in S figures 5, 6 and 7 the joint box 512 in figure 5, the wiring centre 612 and 712 in figures 6 and 7 and the wireless receiver unit 720 in figure 7 is restricted and typically limited to visual indication by power ON indication lamps that illuminate when a main source of electrical power is available to the control system and/or the time switch has provided electrical power to the HW or CH zone control circuitry.

The complete manual creation of the heating system energy efficient control system in figure 7 and described above is time consuming for both the installing contractor and installation engineer because of the complex nature of the electrical connections, the specific control devices needed and due to the individual tailored nature of the pipework distribution system and the extent of building finishes and furnishings within the property.

Figure 8 shows a schematic diagram of a wireless control solution for the system detailed in figure 5 that is accommodated by a controller according to one embodiment that prevents the boiler from continually burning fuel when the temperature of the rooms and the domestic hot water have reached the desired set comfort temperatures during the set ON period of the time switch(es).

Unlike the control solutions described in figures 6 and 7 it is not necessary to conduct a technical site survey of the existing installation before operatives attend site to install the energy efficient control solution detailed in figure 8.

In the embodiment of figure 8, it is necessary to install a wireless cylinder thermostat 817 and two wireless room thermostats 818 and 819. The previous wiring 517, 518 and 519 referred to in figure 5 from the HW, CH1 and CH2 time switch 501 to the central heating boiler 504 and the joint box 512 to subsequently control circulation pump 3 via cable 20 and MV 9 and MVIO via cables 22 and 21 has to be broken into and rerouted in figure 8 to the controller 812 and to an auxiliary controller in the form of a zone extender unit 820. The wiring from the HW, CH1 and CH2 in time switch 801 in figure 8 referred to as 821, 822 and 823 respectively. In figure 8 cabling 827 from boiler 804 and cabling 824 from the circulation pump 803 is also re-routed to the controller 812.

The installing engineer manually connects cable cores from the various control system equipment into pre identified termination blocks within the controller 812 and zone extender unit 820. As described in more detail below, in relation to Figure 9, the controller 812 includes a microprocessor that determines what output signals are provided by the controller in response to input signals from the thermostats or other sensors. The installing engineer determines what type the heating system is (for example, "C-Plan", "C-Plan Plus", "S-Plan, "S-Plan Plus", "W-Plan" or "Y-Plan") and manually sets switches on the controller 812 to select the type of the system and other parameters, for example whether the system is fully pumped or gravity fed. The cable cores from different components of the system (for example boiler, circulation pump, thermostat or other sensor, motorised valves) are inserted into respective pre-determined ones of the termination blocks. The microprocessor selects a control routine in dependence on the selected type of the heating system, and in operation provides appropriate outputs to provide energy efficient control of the heating system in response to the inputs received from the thermostats or other sensors.

In figure 8, once either of the room thermostats 818 and 819 receives a signal from controller 812 and or zone extender unit 820 it controls the boiler 804, the circulation pump 803 and MV 810 and MV 809 effectively switching the boiler OFF during the time switch ON period when the room temperature has reached the desired set point.

Similarly the cylinder thermostat 817 controls the boiler 804 effectively switching the boiler OFF during the time switch ON period when the HW temperature has reached the desired set point. Thus, the controller 412 can override operation of the programmable time controller which would, in the absence of the controller, maintain the boiler ON even though the room or cylinder temperature had reached a desired set point. Thus, the controller can enable a reduction in energy consumption.

The electronic switching circuitry within the controller 812 and extender unit 820 preventing MV 809 and MV 810 from opening and/or the circulating pump 803 from operating inadvertently when either of the other heating zones are calling for heat and the boiler 804 is ON. This system allows the HW and OhM and CH2 to be switched ON and OFF independently of each other. If the time switch in figure 5 has a discreet selector switch to accommodate this mode of operation then to accommodate this, the switch requires to be set to the alternate position.

In the embodiment of Figure 8 there are two separate heating zones, one of which is controlled based on the temperature measured by the room thermostat 818 and one of which is controlled based on the temperature measured by the room thermostat 819. It is a feature of the embodiment of Figure 8 that heating of each of the zones can be controlled independently by the controller. Each zone may be controlled according to a different, timed heating program.

In figure 8, frost protection is provided integrally within the room thermostats 818 and 819. The room thermostats effectively override all the HW, CH1 and CH2 time switches 801 when either or both of them identify that the air temperature has fallen to a preset low level temperature level and subsequently switches the boiler 804 and circulation pump 803 ON and opens MV 809 and MV 810 until such times as the cylinder thermostat 817 and room thermostats 818 and 819 sense that the hot water temperature within the hot water storage cylinder 802 and the room air temperature in each of the central heating zones has reached the preset temperature levels where after the boiler 804 and circulation pump 803 switch OFF and MV 809 and MV 810 close.

In an alternative mode of operation, separate frost protection control procedures are provided for each of the heating zones separately. For example, if the room thermostat 818 for one of the zones indicates that the temperature has fallen below the frost protection threshold temperature, but the room thermostat 819 for the other zone indicates that the temperature has not fallen below the frost protection threshold temperature then the controller switches the boiler 804 and circulation pump 803 ON and opens MV 810 until such times as the room thermostat 818 senses that the room air temperature in that central heating zones has reached the threshold. In that, alternative, mode of operation MV 809 is maintained closed as the room thermostat 819 indicates that the temperature for the other zone is not below the threshold.

In a variant of Figure 8, an additional temperature sensor is installed at or near the boiler 804, for example in the same room as the boiler. In one such variant, the temperature sensor is integral to the controller and the controller is installed at or near the boiler. A separate frost protection procedure, independent of the other frost protection procedures, is provided by the controller based upon the temperature sensed by the additional temperature sensor. If the temperature sensor indicates that the temperature is below a frost protection threshold temperature then the controller S switches the boiler 804 on without opening the valves 809, 810 or pump 803 (unless they are opened in accordance with another frost protection procedure or other control procedure). The boiler 804 is switched off according to the frost protection procedure once the temperature measured by the additional temperature sensor is above the frost protection threshold. That variant can be particularly useful in systems where the boiler is installed in a garage, outhouse or utility room that may be at a temperature significantly below that of the heating zones. Frost problems can be avoided without unneccessary heating of the heating zones.

The controller 812 and the zone extender unit 820 in figure 8 are provided with visual system status indicators that illuminate when each heating zone is activated by the time switch and also provide visual indication of the operational status of the control cylinder thermostat 817 and room thermostat 818 and 819 which illuminate when the set point temperatures of the thermostats have still to be achieved.

Figure 9 details the internal configuration of the primary controller according to one embodiment. The primary controller of Figure 9 can be used as the controller 412 or controller 820 in the embodiments of Figures 4 or 8. The primary controller may comprise a bank of dil switches 903 mounted to a printed circuit board 910 to provide a switch means of adapting the control system in cognisance of the configuration of the pipework distribution system and the type of water circulation chosen, for example a combination of gravity and pumped circulation, or fully pumped circulation systems, and the type, if any, of system frost protection chosen. Oil switch 903, switch 1, allows the selection of fully pumped or gravity HW and pumped CH. Dil switch 903, switch 2, allows the selection of S and C or Y and W plan systems. Oil switch 903, switch 6, allows the selection of boiler only or property frost protection. Oil switch 903, switch 4, allows the selection of the controller's frost protection sensor activation or deactivation.

Although dil switches are used in the embodiment of Figure 9, and provide for particularly simple operation, any other suitable user input device may be used.

The primary controller also comprises a microcontroller or other microprocessor, radio transmitter and receiver unit 904 mounted to a printed circuit board together with a power supply 906 enabling the microprocessor to accept and transmit communication received from hard wired and/or compatible wireless heating control thermostats or sensors that are part of the heating control system and to communicate the appropriate and configurable control options to a combination of triac switching circuits 905 and subsequent termination block 907 to which inputs and outputs are received from and to any hard wired heating devices that are part of the system, for example boilers, circulating pumps, thermostats/sensors and motorised valves 909. The boiler in the system is required for all heating purposes and is therefore common to all heated zones and therefore may always be connected to terminal 6 of connector block 907.

The circulation pump may likewise always be connected to terminal 5 of connector block 907. The mains power supply to the controller may always be connected to terminals 1 and 2 of the connector block 907.

The controller includes a memory, which may be integral to or separate from the microprocessor, and which stores control routines. The control routines may determine the control signals that are provided by the microprocessor in response to any particular signals that are received, for example from sensors, in view of a selected system configuration. The control routine to be used can be selected from the stored control routines, for example based on the system configuration selected using the dil switches.

The microprocessor is operable to output control signals in response to signals received from sensors in order to control operation of the boiler and/or other components of the system, for example at least one circulation pump or valve, thereby to control operation of the system.

The controller may facilitate the termination of one, two or more timed hard wired inputs from a remote central heating programmer for each zone in the system into connector block 907 which in turn activates the hard wired and/or wireless control sensors for that particular heated zone within the heating system and the controller zone status LEDs.

The control signals from the controller control the connection or disconnection of different combinations of inputs to the connector block, thereby controlling the output of control signals to components of the system.

The zone sensors communicate with the controller via hard wired cabling or wireless signals to communicating whether the zone requires heat or not. When a zone sensor is active and calls for heat the controller recognises the zone control requirements and provides mains electrical outputs at the appropriate termination points on connector block 907 to ensure the boiler is switched ON, the pump is switched ON (if required) and if required a motorised valve within the zone is OPENED.

When a zone sensor is active and communicates to the controller that the temperature setting has been reached then the controller recognises the zone control requirements and disconnects the mains electrical outputs to the boiler and to the pump and to the connection of the motorised valve which opened it. The controller also simultaneously provides an electrical output to another terminal within the connector block 907 to which an electrical supply may be taken if an electrical supply is required to CLOSE the motorised valve. The internal conducting and communication paths of the primary controller may be provided on the printed circuit board 910.

The controller is configured to monitor the status of the different components of the system, for example the boiler, the pump, the at least one valve, and the measurements by the sensors. The controller comprises or is connected to an output device. The controller generates status signals based on the monitored statuses and provides the status signals to the output device to provide outputs representative of the status of the system to a user. The output device may comprise a visual display device, for example an LED or array of LEDs. However, any suitable audio, visual, or tactile output device may be used.

Thus, the controller comprises a means of conveying visually to the building user when the boiler is off and the status of the temperature sensors in each of the zones to be heated and, in the case of compatible wireless sensors, when the batteries in the sensors are due to be replaced. The primary controller also comprises a means of conveying to the building user that the frost protection system has activated, or that a carbon monoxide level is above a predetermined threshold, or that a fuel or other storage tank requires refilling. The primary controller will be capable of communicating these status indications to strategically located remote status indicator units within the same heating control system.

The controller will only accept compatible radio control devices, for example thermostats/sensors bonded/registered to an individual primary controller, and will allow replacement and/or additional compatible radio control devices to be bonded/registered to it at any subsequent stage.

The controller may also be provided with additional means of conveying to the building user when a heating system storage tank will soon need refilling. This controller will also switch off the heating system boiler when carbon monoxide has been detected within the property and convey to the building user that the heating boiler has been switched off due to safety concerns.

The controller may also be provided with an internal/integral temperature sensor 908 to provide an additional means of frost protection for the heating system.

The primary controller may also be provided with an integral programmable time controller 901 to provide ON/OFF time control of one or more of the heating zones of the control system.

The controller can be installed in existing systems to improve energy efficiency. The controller is installed in an existing system based on the assumption that the existing system has at least one boiler and one circulating pump and a means of system ON, OFF time control. No assumption is made as to whether the system has a means of controlling space or domestic hot water temperatures, or indeed the type of control for these purposes (for example, thermostatic radiator valves, room thermostats, thermostatic control valves, cylinder thermostats or pipe thermostats), or that the system has any motorised zone valves or the type of such valves (for example, are the valves 2 port or S port valves, power open only, power open and power close) or with or without auxiliary switches?), or how the system has been plumbed in, or whether the existing system control equipment wiring can be fully utilised, or what type of circulation system there is (for example, fully pumped or gravity), or where any of the system equipment is located.

The installation of the controller can provide for energy savings to be made if the heating control system has an energy inefficient control system, and for energy savings to be made if building users currently use an energy efficient heating control system S inefficiently as they can be made aware that they are using their heating control system inefficiently. A control temperature sensor is included in every zone in order that signals can be provided that desired space and/or hot water temperatures have been reached.

It will be understood that the present invention has been described above purely by way of example, and modifications of detail can be made within the scope of the invention.

Each feature disclosed in the description, and (where appropriate) the claims and drawings may be provided independently or in any appropriate combination.

Claims

CLAIMS1. A control system for a heating system, the heating system comprising a boiler, and/or at least one circulation pump and/or at least one valve, wherein the control system comprises:-a controller comprising a microprocessor, wherein the controller is configured to receive at least one input signal from at least one sensor and the microprocessor is responsive to the at least one input signal to provide at least one control signal thereby to control operation of the boiler and/or the at least one circulation pump and/or the at least one valve in dependence on the at least one input signal from the at least one sensor.
2. A system according to Claim 1, wherein the system further comprises a programmable time controller for controlling operation of the boiler.
3. A system according to Claim 2, wherein the programmable time controller is arranged to operate independently of the controller.
4. A system according to Claim 2 or 3, wherein the controller is operable to switch the boiler on or off thereby overriding operation of the programmable time controller.
5. A system according to any preceding claim, wherein the controller comprises output means for providing at least one output signal to the boiler and/or the at least one circulation pump and/or the at least one valve, the at least one output signal being suitable to affect operation of the boiler and/or the at least one circulation pump and/or the at least one valve, for example to switch the boiler and/or the at least one circulation pump and/or the at least one valve on or off.
6. A system according to Claim 5, wherein the at least one output signal comprises the at least one control signal from the microprocessor.
7. A system according to Claim 5, wherein the output means is responsive to at the least one control signal to provide the at least one output signal.
8. A system according to any of Claims 5 to 7, wherein the output means comprises switching means.
9. A system according to Claim 8, wherein the switching means is operable to s connect at least one input or output of at least one of the boiler, the programmable controller, the at least one circulation pump, the at least one valve, and the at least one sensor to at least one input or output of at least one other of the boiler, the programmable controller, the at least one circulation pump, the at least one valve, and the at least one sensor.
10. A system according to Claim 8, wherein the switching means is operable to connect an output from a signal source, for example a mains signal source, to at least one input of the boiler, the at least one valve, or the circulation pump.
11. A system according to any of Claims 8 to 10, wherein the switching means is responsive to the at least one control signal from the microprocessor.
12. A system according to any of Claims 8 to 11, wherein the switching means is responsive to the at least one control signal such that the at least one control signal controls which inputs are connected to which outputs.
13. A system according to any of Claims 8 to 12, wherein the switching means comprises at least one termination block for receiving the ends of wires that in operation receive or provide input or output signals for the boiler, the programmable controller, the at least one valve, the at least one circulation pump and/or the at least one sensor.
14. A system according to Claim 13, wherein the switching means is operable to connect different ones of the ends of the wires connected to the termination block in response to the control output signals.
15. A system according to any of Claims 8 to 14, wherein the switching means comprises at least one triac switch operable to be responsive to the at least one control signal from the microprocessor.
16. A system according to any preceding claim, further comprising input means for receiving user input.
17. A system according to Claim 16, wherein the input means comprises a plurality of user-operable switches, for example dil switches, for selecting a configuration of the heating system.
18. A system according to Claim 16 or 17, wherein the user input is representative of a configuration of the heating system.
19. A system according to any of Claims 16 to 18, wherein the user input means provide for the selection of one of a predetermined plurality of heating system configurations.
20. A system according to Claim 19, wherein the predetermined plurality of heating system configurations comprise at least two, or each, of the "C-Plan", the "C-Plan Plus", the "S-Plan, the "S-Plan Plus", the "W-Plan" and "V-Plan" configurations.
21. A system according to Claim 19 or 20, wherein each of the predetermined plurality of heating system configurations comprises a configuration of a pipework distribution system and/or a type of water circulation.
22. A system according to any of Claims 16 to 21, wherein the user input is representative of a selection of frost protection and/or a selected level of frost protection.
23. A system according to any preceding claim, wherein the controller comprises a memory for storing at least one control routine.
24. A system according to any preceding claim, wherein the controller is operable to perform a selected one of a plurality of control routines.
25. A system according to Claim 23 or 24, wherein the or each control routine determines output signals provided by the controller and/or a dependency of the output signals on the input signals.
26. A system according to any of Claims 23 to 25 as dependent on any of Claims 16 to 22, wherein the controller is configured to select a control routine in dependence on the user input and/or to select the output control signals in dependence on the user input.
27. A system according to any preceding claim, wherein the controller is configured to control the heating of a plurality of heating zones.
28. A system according to Claim 27, wherein the controller is configured to control the heating of each heating zone independently.
29. A system according to Claim 27 or 28, wherein the controller comprises means for setting the timing of heating of each heating zone independently.
30. A system according to any of Claims 27 to 29, wherein the controller is configured to control the heating of a heating zone, and the control system further comprises an auxiliary controller that is operable to receive at least one input from at least one temperature sensor in a further heating zone.
31. A system according to Claim 30 wherein the controller comprises communication means for receiving signals from and/or transmitting signals to the auxiliary controller.
32. A system according to Claim 30 or 31, wherein the controller is operable to control operation of the boiler and/or at least one valve and/or at least one pump to control heating of the further heating zone, for example in dependence on signals received from the auxiliary controller.
33. A system according to any preceding claim, wherein the controller provides a frost protection control procedure, and the controller is operable to switch the boiler on in accordance with the frost protection control procedure thereby overriding operation of the programmable time controller.
34. A system according to Claim 33, wherein the controller provides a frost protection control procedure that determines whether to switch the boiler on in dependence on an input signal received from a room thermostat, and the controller also controls operation of the system to maintain a desired temperature of the room s during normal operation based upon input signals received from the same thermostat.
35. A system according to Claim 33 or 34, wherein the controller provides a plurality of frost protection control procedures, each frost protection control procedure determining whether to switch the boiler on in dependence on an input signal received from a different temperature sensor.
36. A system according to Claim 35, wherein each frost protection control procedure is for providing frost protection for a different room or zone.
37. A system according to Claim 35 or 36, wherein one of the frost protection control procedures is for providing frost protection for a zone where the boiler is located, and at least one other frost protection control procedure is for providing frost protection for at least one further, different zone, and the frost protection control procedure for the zone where the boiler is located comprises switching the boiler on without operating a circulation pump or valve that provides heating to the at least one further zone.
38. A system according to any preceding claim, wherein the controller comprises monitoring means for monitoring the status of at least one of the boiler, the programmable time controller, the at least one circulation pump, the at least one valve, and the at least one sensor and for providing at least one status signal representative of the status.
39. A system according to Claim 38, wherein the system further comprises output means for providing output to a user in response to the at least one status signal.
40, A system according to Claim 39, wherein the output means comprises display means, for example comprising at least one LED or other light.
41. A system according to Claim 39 or 40, wherein the output means is configured to convey to a user that a heating system storage tank requires refilling, and/or that carbon monoxide has been detected and/or that the boiler has been switched off due to safety concerns.
42. A system according to any preceding claim, wherein the at least one sensor comprises at least one temperature sensor, for example at least one thermostat.
43. A system according to any preceding claim, wherein the at least one sensor comprises a carbon monoxide sensor and/or a fuel level sensor and/or a frost protection sensor.
44. A method of installing a control system for a heating system, the heating system comprising a boiler and/or at least one circulation pump and/or at least one valve, and the method comprising:-providing a controller comprising a microprocessor; and arranging the controller to receive at least one input signal from at least one sensor, wherein the microprocessor is configured to provide at least one control signal thereby to control operation of the boiler and/or the circulation pump and/or at least one valve in dependence on the at least one input signal from the at least one sensor.
45. A method according to Claim 44, that is a method of adapting an existing heating system, and optionally comprises replacing a wiring unit of the existing heating system with the controller.
46. A method according to Claim 45, wherein the control system is a control system according to any of Claims 1 to 43.
47. A method of controlling a heating system, the heating system comprising a boiler, and/or a circulation pump and/or at least one valve, and the method comprising:-receiving at least one input signal from at least one sensor and providing at least one control signal thereby to control operation of the boiler and/or the circulation pump and/or the at least one valve in dependence on the at least one input signal from the at least one sensor.
48. A method according to Claim 47, wherein the control system is a control system according to any of Claims 1 to 43.
49. A method substantially as described herein with reference to the accompanying drawings.
50. A system substantially as described herein with reference to the accompanying drawings.