Problem with Gas Combi Boiler Heating

Question

Hi

Hope somebody can help

I have a Protherm 80e combi boiler. In the last two day's the central heating has only heated the rad's so that they are not cold. Saying they are warm would be stretching the truth. The boiler runs ok but when the display hit's 41 the boiler stops heating. When it drops to 28 the boiler automatically starts heating again.

The problem only applies to the CH. The water from our hot taps is very hot and the boiler automatically comes on when a hot tap is turned on.

I cleaned the secondary heat exchanger which was full of dirt and fitted a new CH thermistor but still have the same problem.

Would anybody have any idea what else could be wrong???

Thanks on advance for any suggestions offered

:-)

Answer 1

Perhaps you need to vent air from the rads, or the pump is playing up.

Answer 2

Try changing the primary thermistor,renew the hw thermistor and the limit thermostat,if the fault still persists then its likely that the pcb is faulty.