the boiler works sometimes I have to bang the boiler on the sliding door for it to work? I have checked the wiring and the circuit board all ok. the pump runs and you can here the fan running. Thought it might be the over limit stat on the boiler?
if the over limit (hi limit) stat is the problem neither the pump or fan should run, sounds like either the fan is failing to get to speed, the flue is partially blocked or the aps is failing
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix home heating systems.