WO2010142993A2

WO2010142993A2 - Heating system

Info

Publication number: WO2010142993A2
Application number: PCT/GB2010/050972
Authority: WO
Inventors: Martin Howes
Original assignee: Martin Howes
Priority date: 2009-06-12
Filing date: 2010-06-10
Publication date: 2010-12-16
Also published as: WO2010142993A3; GB0910157D0; GB2470958A; EP2440854A2

Abstract

A heating system comprises a boiler, a pump for circulating a fluid through the boiler and control equipment including a programmable controller remote from the boiler arranged to generate an electrical boiler control signal in response thereto, wherein the boiler is arranged to generate an electrical control signal for the pump, so that the pump can continue to be operated after operation of the boiler, the control equipment being electrically connected to a wireless transmitter which transmits the boiler control signal to a wireless receiver electrically connected to the boiler and the wireless receive being arranged to provide a boiler control signal to the boiler in response to receiving a signal from the wireless transmitter. The invention is particularly applicable for fitting a modern boiler requiring a permanent live to older installations where only a switched live was present.

Description

Heating System

The present invention relates to a heating system and particularly, but not exclusively, to a domestic heating system.

An older domestic central heating system may have the components illustrated in Figure 1, comprising a controller 1 connected to a mains electricity supply 2, the controller being programmable to provide a switched live connection 3 to a boiler 4. The switched live 3 may pass through a thermostat 5, such that during an operative period, as defined by the controller, the boiler may still be switched off when the thermostatic device 5 reaches a predetermined temperature. The thermostatic device 5 may be a thermostat associated with a hot water cylinder 6, as in the embodiment depicted, where the boiler heats the water in a primary circuit of the hot water cylinder, or alternatively the thermostat could be a room thermostat for detecting the ambient temperature in a region to be heated, wherein the boiler would provide a heating fluid for heating radiators within the region. In most applications the boiler will heat both the hot water and provide space heating and this will normally require two separate control circuits employed in parallel. However, for simplicity, only one has been shown in Figure 1.

A pump 7 is also provided for circulating the fluid in the primary circuit and this is electrically connected in parallel with the boiler 4. When the switched live connection to the boiler is live, the switched live connection to the pump 7 is also live and the pump 7 circulates the primary circuit of the heating system.

The controller 1 and thermostat 5 will often be located remotely from the boiler 4.

The controller may, for example, be upstairs and the boiler downstairs, as represented by the dashed line 8. In the Figure 1 embodiment, the pump 7 has been shown located adjacent to the boiler, but it could alternatively be located adjacent to the controller or thermostat 5.

For safety reasons, all the electrical power for the complete heating system of Figure 1 has to be derived from a single mains supply 2. This ensures that an engineer, disconnecting a mains connection, disconnects the complete system from the mains. It also ensures that the system cannot be inadvertently connected to different phases in a property having a three phase supply.

In the Figure 1 arrangement, the thermostatic device 5 is shown located between the controller and the boiler. However, all the wiring associated with the controller and thermostat may be connected at a common wiring centre. The requirement for a single connection to the mains results in there normally being at least a three core cable (including earth, neutral and a switched live) between the control equipment, consisting of the controller, one or more thermostats (or switched outputs from a motorised valve, not shown) and the boiler, located remotely of the control equipment.

In more modern heating systems, there is a requirement for the pump of the heating system to continue operation after operation of the boiler is terminated. This removes residual heat from the boiler, utilising that heat and preventing the boiler from tripping out due to an over temperature cut-out occurring as a result of residual heat in the casing of the boiler. The components of such a heating system may be arranged as illustrated in Figure 2, where a single mains electricity supply 2 provides both a controller 1 and boiler 4 with electrical power. In this system, in contrast with the system of Figure 1, an additional permanent live 9 is provided, which enables a control mechanism 17 within the boiler 4 to control operation of the pump separately from operation of the boiler, enabling the pump 7 to continue operating (or over run) for a period after the boiler has been switched off.

When installing a system as illustrated in Figure 2 in a new building, it is necessary to provide a four core cable between the controller or control equipment and the boiler. This may require specific cable routes to be accommodated in the building when the building is constructed. If a modern boiler, requiring both permanent live and a switched live is to replace an existing boiler, as illustrated in Figure 1, requiring a switched live only, it is necessary to obtain a permanent live from the controller, or at least from the mains supply connection 2, and to run a separate cable from this to the boiler 4. This is both time consuming and can be unsightly. Furthermore, if the pump was previously installed at a location in the vicinity of the control equipment, it will also be necessary to run a cable 10 for the pump live supply from the boiler 4 to the pump 7 (possibly via the wiring centre).

According to the present invention there is provided a heating system comprising: a boiler; a pump for circulating a fluid through the boiler; and control equipment including a programmable controller remote from the boiler arranged to generate an electrical boiler control signal, wherein the boiler is arranged to generate an electrical control signal for the pump so that the pump can continue to operate after the boiler has been switched off, the system further comprising: a wireless transmitter electrically connected to the control equipment; and a wireless receiver electrically connected to the boiler, wherein the wireless transmitter is arranged to transmit the boiler control signal to the wireless receive and the wireless receiver is arranged to provide a boiler control signal to the boiler in response to receiving the signal from the wireless transmitter.

Employing the present invention provides a heating system that enables a boiler, requiring both a permanent live and switched live, to be electrically connected to only a permanent live and to then generate the switched live locally by switching the permanent live in response to a control signal received wirelessly. In this manner a transmitter can be connected to a live, neutral and earth connection at, or in close proximity to, the controller (or the transmitter could be incorporated in the controller) and also connected to the switched live from the controller, or control equipment, which the transmitter then uses to transmit a wireless control signal. A receive located in close proximity to the boiler, where a live, neutral and earth connection will also be present for powering the receiving, can then use the permanent live to create, in response to receiving the wireless signal from the transmitter, the switched live required by the boiler. The boiler then has a permanent live and a switched live and the boiler can thus provide an output control signal for the pump even after the switched live to the boiler has been terminated.

A system in accordance with the present invention may thus only require a live, neutral and earth connection between the controller or control equipment and the boiler.

Thus such a system can be created from a traditional heating system, as illustrated in Figure 1, utilising an existing three core cable between the controller and boiler to provide a permanent live, neutral and earth and using a wireless signal to transmit a control signal to generate the switched live locally at the boiler.

A system in accordance with the present invention may be particularly advantageously employed where the control equipment and the boiler are both connected to a mains electricity supply through a single connection point, requiring only a single connection to the mains. This may be desirable where an existing single point connection can be utilised. In this arrangement, the boiler may then advantageously provide a pump control signal for the pump along a wired connection to the pump.

The present invention avoids the need for an electrical connection to transmit the switched live signal from the controller to the boiler. There is therefore no need for the controller or control system to be electrically connected to the boiler and in an alternative embodiment of the present invention the boiler is connected to a mains electricity supply at a first point of connection, the control equipment is connected to a mains electricity supply at a separate second point of connection (with no live or neutral connection provided between the control equipment and the boiler other than by way of the mains supply). This arrangement enables the controller and boiler to both be connected locally to the mains supply, which may be particularly advantageous when replacing an existing boiler, avoiding the need to use or replace existing wiring between the controller and boiler.

Depending on the location of the pump, it may be preferable that the system further comprise a second wireless transmitter connected to the boiler, for receiving a pump control signal from the boiler, and a second wireless receiver connected to the pump where, in response to receiving a pump control signal from the boiler, the second transmitter transmits a signal to the second receiver causing the second receiver to provide a pump control signal to the pump. Such an arrangement is particularly advantageous where the pump is located close to the controller or control equipment and it is especially applicable to a system where a new boiler, requiring both a permanent live and a switched live, is to replace a boiler having only a switched live connection, to which the pump would previously have been electrically connected in parallel with the boiler. It is particularly advantageous if the boiler control signal is a switched live connection and the pump control signal is a switched live connection, permitting standard boilers and pumps to be used which are controlled simply by controlling the switched live to them.

The system may advantageously comprise a thermostatic device which provides a switched live to the transmitter electronically connected to the control equipment, thus a conventional arrangement of thermostatic device, such as a room or tank thermostat, may be employed in the conventional manner.

The control equipment may comprise a motorised valve connected to the programmable controller, which valve has an electrical switch that provides the boiler control signal to the transmitter connected to the control equipment switched live.

According to the second aspect of the present invention there is provided a wireless transmitter/receiver arrangement for a heating system as described above, the arrangement comprising two wireless transmitter/receiver pairs, each pair arranged to be connected to a mains electricity supply, to receive a further switched live connection and generate a wireless signal to the other transmitter receiver pair in response thereto, each transmitter receiver pair being further arranged to receive a signal from the other transmitter/receiver pair and generate a switched live output signal in response thereto.

The invention will now be described, by way of example only, with reference to the accompanying figures in which like reference numerals have been used throughout to indicate like parts and of which:

Figure 1 illustrates a conventional older style prior art heating system; Figure 2 illustrates a modern prior art heating system;

Figure 3 illustrates a first embodiment of a heating system in accordance with the present invention; Figure 4 illustrates a second embodiment of a heating system in accordance with the present invention; and Figure 5 illustrates a third embodiment of the heating system in accordance with the present invention.

Referring now to Figure 1, a traditional heating system, as previously described, comprises control equipment including a controller 1 connected to a mains supply 2 and a thermostat 5. The control equipment provides a switched live 3 to a boiler 4 over a three- core cable 11. This provides an earth, neutral and switched live to both the boiler and a pump 7 electrically connected in parallel with the boiler. Therefore when the controller and thermostat are switched to connect the switched live 3 to the live of the mains, both the boiler and pump are actuated simultaneously. The pump 7 pumps heated water around a heating circuit, which in the embodiment shown is the primary circuit 12 of hot water cylinder 6.

For reasons of simplicity Figure 1 illustrates only the basic components of such a system. In practice, however, the system may include other components such as relays and is likely to include one or more motorised valves, in either what is termed an S-plan or Y- plan arrangement, or variations thereof. These are well known in the art and in the example of Figure 1 the switched live from the thermostat 5 would control the motorised valve in the primary circuit 12 of the hot water cylinder 6. The switched live 3, received by the boiler 4, would be derived from an end switch of the motorised valve, such that the boiler would only be energised when the valve was open.

The Figure 2 arrangement differs from that of Figure 1, in that a permanent live 9 is also provided between the controller 1 and the boiler 4. The boiler 4 controls the pump live 10 to the pump 7. Because the pump live, is derived from the permanent live, the pump live can remain live after the switched live has been disconnected and the boiler switched off, thus permitting residual heat to be extracted from the boiler 4.

Referring now to Figure 3, a heating system in accordance with the present invention comprises the same components as (and functions in a similar manner to) the system of Figure 2, with the exception that a transmitter 13 and a receiver 15 are additionally provided, both being connected to the mains via the controller 1. The transmitter is connected to the switched live 14 from the thermostat 5, and transmits a wireless boiler control signal 17 in response thereto. Any suitable wireless control technology may be employed, for example that used in the Survic ™ TLX RFD radio frequency digital room thermostat.

The receiver 15, in dependence on the signal 17 received from transmitter 13, uses the permanent live from cable 11 to provide a switched live 16 to the boiler 4, thus the switched live 14 is effectively transmitted wirelessly to the boiler 4.

The boiler 4 is actuated in dependence on the boiler control signal in the form of switched live 16. When the switched live 16 is disconnected, a control mechanism 17 within the boiler 4 maintains the pump live signal to the pump 7 for a predetermined period of time so that fluid continues to be circulated in the boiler, extracting residual heat from the boiler 4.

The arrangement of Figure 3 enables pump "overrun" to be achieved using only a three core cable connection between the controller and the boiler. Thus the boiler of the Figure 1 system can be replaced with one having a pump over run facility by wiring in the transmitter, receiver and new boiler in the manner disclosed in Figure 3, without the need to provide any additional electrical wiring between the controller 1 and boiler 4.

In the arrangement of Figure 3, a control signal between the controller 1, or a motorised valve (not shown, as discussed with reference Figure 1) and the boiler 4 is achieved by means of wireless signal 17. Thus an electrical connection between controller 1 or control equipment 1, 5 and the boiler 4 is no longer required. In Figure 4 an alternative arrangement is illustrated where the cable 11 of Figure 3 embodiment has been omitted. Here the boiler 4, receiver 15 and pump 7 are connected to a separate local mains supply 19, which may be a three pin socket, or similar, located in close proximity to the boiler 4.

Referring to Figure 5, a third alternative embodiment is illustrated where the pump

7 is located closer to the controller 1 than the boiler 4. In this embodiment two transmit/receive units 13,21 and 20,15 (which units may be identical) are located adjacent to the controller 1 and boiler 4 respectively, with each being connected to a respective permanent mains supply 2, 19. The transmit/receive unit 13, 15 operates in the manner previously described with reference to Figure 4. The additional transmit/receive unit 20, 21 is used to convey the pump live signal 18 from the boiler 4 to the pump 7, in the same way as the transmitter 13 and 15 transmit the switched live signal to the boiler 4. This permits the pump 7 to be operated remotely from the boiler without the wired connection between the two.

In the Figure 5 embodiment the switched live is, in this figure, shown to be generated by a motorised valve 22, which valve 22 is operated and connected in the normal manner. This is one example of any number of alternative combinations of components that may be employed with a system in accordance with the present invention, as defined by the appended claims. Particularly the control equipment may be arranged in any number of ways and comprise a number of components to provide the switched live. In particular, a number of different timer circuits within the controller, together with associated thermostatic devices, may be employed with a common boiler to provide heating to different areas and /or to provide both hot water and space heating. Also with reference to Figure 5, separate mains connections 2, 19 are shown. However, a single connection point could be provided with a three core cable supplying a common live neutral and earth connection to the boiler, or control equipment, located remote from the mains connection 2 or 19.

Claims

1. A heating system comprising: a boiler; a pump for circulating a fluid through the boiler; and control equipment remote from the boiler arranged to generate an electrical boiler control signal, wherein the boiler is arranged to generate an electrical control signal for the pump so that the pump can continue to operate after the boiler has been switched off, characterised in further comprising: a wireless transmitter electrically connected to the control equipment; and a wireless receiver electrically connected to the boiler, wherein the wireless transmitter is arranged to transmit the boiler control signal to the wireless receiver and the wireless receiver is arranged to provide a boiler control signal to the boiler in response to receiving the signal from the wireless transmitter.

2. A system as claimed in Claim 1, wherein the boiler and the control equipment are both connected to a mains electricity supply through a single connection points.

3. A system as claimed in Claim 1 or 2, wherein the boiler provides a pump control signal to the pump along a wired connection to the pump.

4. A system as claimed in Claim 1, wherein the boiler is connected to a mains electricity supply at a separate second point of connection to the control equipment.

5. A system as claimed in Claim 1, 2 or 4, further comprising: a second wireless transmitter which is connected to the boiler for receiving a pump control signal from the boiler; and a second wireless receiver which is connected to the pump wherein, in response to receiving a pump control signal from the boiler, the second transmitter transmits a signal to the second receiver causing the second receiver to provide a pump control signal to the pump.

6. A system as claimed in any preceding claim, wherein the boiler control signal is a switched live connection.

7. A system as claimed in any preceding claim, wherein the pump control signal is a switched live connection.

8. A system as claimed in any preceding claim, comprising a thermostatic device which provides a switched live to the transmitter electrically connected to the control equipment.

9. A system as claimed in Claim 7, wherein the control equipment comprises a motorised valve, which valve comprises an end switch that provides the boiler control signal to the transmitter, which control signal is a switched live.

10. A system as claimed in Claim 8, wherein the motorised valve controls primary fluid flow in a hot water cylinder or in an area to be heated.

11. A system as claimed in any preceding claim, wherein the control equipment includes a programmable controller.

12. A wireless transmitter/receiver arrangement for a system as claimed in Claim 5, comprising two transmitter/receiver pairs, each pair being arranged to be connected to a mains electricity supply, to receive a switched live connection and to generate a wireless signal to the other transmitter receiver pair, each transmitter receiver pair being further arranged to receive a signal from the other transmitter/receiver pair and generate a switched live output signal in response thereto.

13. A heating system substantially as hereinbefore described with reference to and/or illustrated in one or more of Figures 3 to 5 of the accompanying drawings.