boilercentral-heatingthermostat
My boiler kicks in when the thermostat asks it to, but when my room thermostat asks the boiler to fire up, nothing happens.
My room thermostat clicks on, and lights up so I think it can tell the temperature of the room.
Please can anyone help with my problem?
Boiler: ideal classic lxff
Room thermostat: horstmann HRT 2
I called a number of Central Heating contractors and also Uponor, the company that makes the controller.
I was told that the clicking noise comes from the soft-fuses inside the controller trying to reset. They said box has failed and needs to be replaced by an electrician. Since the controller is the simplest model in their range, there are no diagnostic LEDs or other features that indicate a fault status, except the clicking noise of the soft-fuse.
The repair should only be about an hours labour plus cost of a new controller box.
A very blind shot: Air in the heating system? You have to de-air the central heating radiators, there should be a special vent on it, which might look like this:
You better put some bowl on the floor before you open the vent. If water starts to run out of it immediately, eveything is ok. If not and you hear the sound of leaking air, there's air in the radiator which has to be let out. Be careful, the air is usually quite smelly and water which starts to run out of the vent is usually very dirty and dark at first.
Best Answer
The room thermostat does not control the boiler directly. Instead, it controls a circulating pump that draws heat from the boiler and delivers it to the radiator(s) in the room. It is the removal of heat that subsequently causes the boiler to fire, when its thermostat indicates that its internal temperature has dropped because of the heat removal.
It sounds like either the circulating pump or the relay that controls it has gone bad and needs to be replaced.