Potterton Prima F 40 fault

[Mani]

hello,

I hope someone might be able to help with an intermittent problem we have with our 7 year old Potterton Prima F 40 boiler.

Every once in a while, whilst running it makes a continual clicking noise for approx 3-5 seconds which causes some vibration (is it one of the solenoids failing?). As I said it's intermittent and sometimes it can occur for a second then go away.

I've had an engineer look at it but it does'nt repeat the fault whilst he's there! He changed the main burner soleniod because it also, occasionally, lights the pilot light but does'nt fire up the main burner.

Any theories as to what the engineer could change would be gratfully received - new PCB perhaps? I'm also concerned it might be dangerous. kind regards,

Mani

[Ed Sirett]

I would hazard a guess that the micro switch in the air pressure switch is iffy. Normally there is a fair bit of hysteresis in the air pressure switch but if the switch is bad it might be making bad contact this would make a clicking noise on the main relay on the main control board.