Horsmann h37 not sending power to boiler of thermostat...

[Jonathan Sherratt]

Hi there I have an old Horsmann H37 controller which is not powering up my smart thermostat or firing up the boiler even for hot water even though it says it's on. Could this be a problem with the boiler or do I need a new controller?

Thanks

 

[stem]

It depends upon the type of system you have. If your system has a two port motorised valve controlling the hot water, then the programmer and thermostat will only control the motorised valve. The motorised valve in turn is what actually starts the boiler.

The fault you describe is more often failure of the motorised valve than the programmer or thermostat.

For a more definite reply you will need to provide details of your heating system. It sounds like you likely have a hot water cylinder (ie not a combi boiler) so, search S-Plan, S-Plan+ and Y-Plan to identify your system.