Potterton Profile 80e

[Dabs]

Boiler fires up ok on heating.

On hot water, boiler starts to fire up and then switches off and the fan cyles like this for a period of time before eventually firing up ok.

Would anybody be able to tell me what is causing this. Thx

 

[Dabs]

I ended up changing the whole PCB 407677.

What happens now is the boiler fires up first time on CH or DHW demand, runs for about 1 minute and then cuts out, I'm assuming it is overheating. If it does overheat do I have to reset the switch or will it start working again after cooling off for a while? And if it does start working after a while without pressing the reset switch does this mean its not a overheating problem? (Also the reset switch is so flimsey that pressing it doesn't seem to do anything, should I hear it click or something?). The pump has power and I can hear it spinning so seems to be working ok so not sure what the problem is. Maybe blockage somewhere else but don't know how to check. Can anybody help?

 

[75pete]

Try to check that the pump is free of air by removing the large screw in the face of the pump [ bleed screw ] and see if any water drips out.
Now bleed your rads. If you do not get water from the rads upstairs, check the small F/E tank in the loft.
If it has water in it you may have a blockage in the fill pipe.
This would be checks any diyer could do.