Boiler not lighting

[FreezingDave]

My Potterton Prima 50F boiler is playing up. Tries to ignite several times before actually managing it, has got worse over past week and today has only managed 10 minutes before turning off and now won't come back on at all. I've been told that it could be the air pressure switch. I can hear the switch clicking quietly when boiler starts trying to ignite and then once more loudly when it manages to ignite. I've tried checking the power at the 3 terminals on the switch. 2 (white/brown) are live all the time that the pump is running and the 3rd one(orange) becomes live AS WELL when boiler decides to light. Is it right that all 3 are live once the boiler is running or should one terminal 'turn off' when the switch operates? Or could it be something totally different to the air pressure switch?
Thanks

 

[swbaxter]

Dave

Did you ever get anywhere with this? I now have a Prima 50F doing exactly the same thing.

One interesting thing I've found is that Potterton's site doesn't even achknowledge the existence of the Prima Fs. Of the models the site does mention, the Prima Cs and Suprimas look very different but the Profiles look just like my boiler. So I'm not even sure this boiler is a Prima 50F!!

From other posts, I'd take a guess you had to replace the PCB. I'd be interested to know.

Steve Baxter