There is a constant fan noise coming from my Potterton Puma boiler (either 80 or 100 series). It goes away when the boiler is on (heating water) but is at its loudest when the boiler is in standby mode (or hot water only, not heating).
Also does anyone have any instructions how to program the electrical timer (just bought a flat with the boiler installed but no instructions)?

Orri Petursson, January 2006

Orri, did you solve your noisy fan problem? I have the same issue now (2009). I tried to retrieve the fan but soon realise that it could be a dangerous job.

Dave

Dave, July 2009

hi, Orri it sounds like the pump , to test this put a screw driver against the pump casing and put your ear to the end of the handle,you will hear the pump runing, this should detect the noise, you will hear a slight noise off the pump but if its very loud then i would say that is the problem

bob roberts, January 2006