I posted some time ago concerning my Potterton, which had a new PCB earlier in the year, but is now locking out again.
Geoff suggested measuring the voltage at the solenoid valve, which I have now done, and it looks OK, going up to about 180V when the sparking starts. You can also feel it working, so I am pretty sure it's working.
If you reset it several times in a row, it will eventually light and will then work quite well, unless it is off for a while - ie., overnight.
I have taken the cover off and verified that it is sparking in the right place, and that the spark looks quite healthy.
What I now need to understand is how the ignition process works - I think that it lights a pilot jet first, and as long as there is a flame, it then turns on the whle burner. Is that correct? What senses the initial flame, and is there a 2nd stage to the solenoid valve, or is it a separate valve?
With the cover off, there is no audible indication of gas or any smell, so it seems that not enough is getting through. Could it be a blocked jet or something?
I have heard that the pressure switch can be faulty on these - would that have the same effect?
Any help would be appreciated...
Thanks.
-- Colin Swan