Gloworm Fuelsaver 100F cuts out before the radiators get hot.?
Old boiler but has been working fine.Has just started cutting out before radiators get hot. Radiators get warm but not hot.Pump ok,valves open and room stat seems ok.Hot water from cylinder ok. Boiler fires up for a few minutes then cuts out.
I had a very similar problem with an 80FF, the problem was the exhaust fan which started ok, but when it got hot would slow down, once the airflow gets too low the pressure differential switch trips out again and it shuts down.
The fans on these boilers only seem to last a couple of years before the bearings go and they have to be replaced.