T
Tawny64
I am crrently working on the above, it has had the low and high thermostats and overheat thermost recently replaced together with the igniter, pilot jet and thermocouple. Room stat is operating as it should and the sytem pump is new. The boiler will only run for a short while, cycling between burner on and off. Flame is strong and blue with no sooting (Burner box all clean as a whistle) the house never getting up to temperature. System has been recently flushed and refilled with no air locks, rads get warm but never hot (all valves are open fully). The 3 way valve is opening and supplying heat to the HW cylinder when switched and in the auto position. I am thinking there is a main gas valve fault, yet the boiler will fire up and cycle but only for a short burn time which does not ever heat the radiators or HW up to temperature even if the roomstat is set to maximum. I am reluctant to replace the gas valve (all other work being undertaken prior to my involvement) if this indeed may not be the problem. Switching the boiler thermostat from high to low or vice versa and bypassing the overheat thermostat (new as above) make no difference. Power is not being lost at the solenoid when the burner goes out and the system pump runs continuously when the boiler is switched on. Maximum run time varies (around 15 mins burner on max) even with the house asolutely frezing and the room stat calling for heat. Any suggestions?
