GB2363450A

GB2363450A - Service period safety device for combustible fuel heating apparatus

Info

Publication number: GB2363450A
Application number: GB0012900A
Authority: GB
Inventors: Alan Norton
Original assignee: ISYS CONTROLS Ltd
Current assignee: ISYS CONTROLS Ltd
Priority date: 2000-05-27
Filing date: 2000-05-27
Publication date: 2001-12-19
Also published as: GB0012900D0

Abstract

The safety device (1) is provided to require an engineer to service a central heating boiler (2) within a predetermined period, the service period. The safety device (1) has a disabling switch (4), a timer (5) and a reset switch (9). The device may include a quartz crystal (6), a micro controller (7), a non-volatile memory (8), a battery backup and a programmer (3). In the preferred embodiment the quartz crystal (6) provides the time base for the circuit and a count of the elapsed time is maintained within the counter of controller (7). The counting continues until the servicing period is reached, at which time the controller (7) sends a signal to the disabling switch (4) which prevents the boiler (2) from functioning. The heating apparatus may be disabled by preventing either, the supply of fuel to the boiler (2), the ignition of the fuel within the boiler (2) or a programmer (3) from starting the boiler (2). In order to restart the boiler (2), reset switch (9) is pressed which resets the counter in the controller (7) to zero allowing the boiler (2) to function again. Unauthorised access to the reset switch (9) may be prevented and/or it may be concealed.

Description

2363450 CENTRAL HEATING SAFETY DEVICE The present invention relates to

safety devices for heating systems, and particularly, but not exclusively, to safety devices for domestic gas central heating systems.

In the LIK there are statutory requirements placed upon the landlord of domestic premises in relation to the servicing of central heating systems. These include Regulation 36 of the Gas Safety (installation and use) Regulations 1998 which state that:

"A landlord shall ensure that each appliance and flue is checked for safety within 12 months of being installed and at intervals of not more than 12 months since it was last checked for safety."

The approved code of practice for these regulations states that "A landlord shall take all reasonable steps to gain access". The code of practice does not define what constitutes all reasonable steps but goes on to state that "It is finally for a court to decide whether all reasonable steps have in fact been taken and whether a landlord is guilty of an offence".

However, some tenants are unwilling to cooperate -with their landlord and may prevent the landlord and/or his engineer from gaining access to the central heating apparatus. Existing central heating systems do not force a tenant to allow access to the heating apparatus which leaves the landlord in the difficult position of not knowing whether he has taken "all reasonable steps" to service the apparatus.

Preferred embodiments of the present invention seek to overcome the above disadvantages of the prior art.

According to the present invention, there is provided a safety device for a combustible fuel heating apparatus, the safety device comprising.disabling means for preventing the functioning of the heating apparatusl timer means for automatically activating said disabling means after a predeterill I ned period, and resetting means for resetting said timer to the beginning of said predetermined period and deactivating said disabling means to enable operation of the heating apparatus.

By providing a heating apparatus with a safety device containing a disabling means controlled by a timer set to disable the apparatus after a predetermined period of time (which is approximately the period when servicing is required), the advantage is provided that if the device is not serviced within the prescribed time period the heating apparatus will fall to operate. If such a device is used within the central heating system of a rented domestic property, the advantage is provided that the heating apparatus appears to have simply failed, and it is therefore necessary for an engineer to visit the premises to apparently repair the apparatus.

The resetting means may be concealed.

Unauthorised access to said resetting means may be prevented.

In a preferred embodiment, the combustible fuel for the heating apparatus is gas.

In a preferred embodiment said disabling means is adapted to prevent the supply of fuel to the heating apparatus.

In another preferred embodiment said disabling means is adapted to prevent the ignition of fuel within the heating apparatus.

In a further preferred embodiment said disabling means is adapted to prevent a programmer for the heating apparatus from starting the heating operation of the heating apparatus.

In a preferred embodiment said timer means includes a quartz crystal timer device.

In a preferred embodiment said timer device includes a battery backup power supply.

By providing a battery backup power supply for the timer means, the advantage is provided that in the event of a power failure, whether accidental or deliberate, the timer means is not reset.

In another preferred embodiment said timer device includes a non-volatile memory for storing data relating to said predetermined period in the event of power loss to the timer.

By providing the timer device with a non-volatile memory, the advantage is provided that in the event of an interruption in the power supply and/or a failure or draining of a battery backup power supply if provided, the counter device does not reset.

A preferred embodiment of the invention will now be described, by way of example only and not in any limitative sense, with reference to the accompanying drawings, in which:- Figure I is a schematic diagram of an embodiment of the present invention.

A safety device I for a central heating boiler 2 is connected to a central heating programmer 3. The safety device I comprises a disabling means in the form of a disabling switch 4 and a timer 5. The timer 5 comprises a quartz crystal counting device 6 connected to a micro controller 7 to which is a non-volatile memory is also connected. Timer 5 also includes a reset switch 9, which is generally concealed and/or to whic h unauthorised access is prevented.

When a central heating system including the central heating programmer 3 containing the safety device 5 of the present invention is installed, a counter which is part of micro controller 7 has a count of zero. The quartz crystal 6 provides the time base for the circuit and a count of elapsed minutes is maintained within the counter of micro controller 7. Every minute the count is written to non-volatile memory 8 which holds the last thirty two counts to allow for error detection.

The circuit is powered by the same external power source as the gas central heating programmer 3 and is also supplied with a battery backup (not shown) in the event that the main supply of power is cut, for example if the central heating apparatus is turned off during the summer. It Is important that the count is maintained during that period. In the event that the battery backup power supply also fails, the count is maintained within the non-volatile memory and when mains power returns, the non-volatile memory 8 is read by micro controller 7 and the highest of the 32 recorded counts is taken as the latest lapsed time.

The counting continues until the number of minutes within the required servicing period is reached, for example 525600 for one year. Once the count reaches this figure, micro controller 7 sends a signal to disabling switch 4 which is switched on, thereby preventing the operation of output relays in programmer 3. As a result, boiler 2 cannot function.

A person not knowing that a safety device 5 is fitted to the programmer 3 would be unable to restart the central heating system and is therefore more likely to allow an engineer access to the central heating system, at which time servicing can be carried out.

In order to restart the central heating system, reset switch 9 is pressed which resets the counter in micro controller 7 to zero. This in turn disengages the disabling switch 4, allowing the central heating programmer to function. If after another year the count reaches 525600 minutes, the same disabling process will occur again. If a service occurs before that time period ends the engineer, as part of the service, must press the reset switch 9, In order to prevent unauthorised persons from operating the reset switch 9, It is concealed and/or operable only by persons in possession of a relevant key or code. The switch 9 is located either within the easing of the programmer 3 or boiler 2 so that it is accessible only once the casing has been removed.

Possible other switches include a magnetic reset switch which is reset by the introduction of a magnet adjacent the switch. Alternatively an access to the switch may be provided through a hole in the programmer unit.

It will be appreciated by persons skilled in the art, that the above embodiment has been described by way of example only and not in any limitative sense, and that various alterations and modifications are possible without departure from the scope of the invention as defined by the appended claims. For example, the safety device may be incorporated within the central heating boiler rather than being part of the programmer.

Claims

1. A safety device for a combustible fuel heating apparatus, the safety device comprising- disabling means for preventing the functioning of the heating apparatus', timer means for automatically activating said disabling means after a predetermined period; and resetting means for resetting said timer to the beginning of said predetermined period and deactivating said disabling means to enable operation of the heating apparatus.

2. A safety device according to claim 1, wherein said resetting means is concealed.

3. A safety device according to claim 1 or 2, wherein unauthorised access to said resetting means is prevented.

4. A safety device according to any one of the preceding claims, wherein the combustible fuel for the heating apparatus is gas.

5. A safety device according to any one of the preceding claims, wherein said disabling means is adapted to prevent the supply of fuel to the heating apparatus.

6, A safety device according to any one of the preceding claims, wherein said disabling means is adapted to prevent the ignition of fuel within the heating apparatus.

7, A safety device according to any one of the preceding claims, werein said disabling means is adapted to prevent a programmer for the heating apparatus from starting the heating operation of the heating apparatus.

8. A safety device according to any one of the preceding claims, wherein said timer means includes a quartz crystal timer device.

f

9. A safety device according to any one of the preceding claims, wherein said timer device includes a battery backup power supply.

10. A safety device according to any one of the preceding claims, wherein said timer device includes a non-volatile memory for storing data relating to said predetermined period in the event of power loss to the timer.

11. A safety device for a combustible fuel heating apparatus, the safety device substantially as hereinbefore described with reference to the accompanying drawings.