Potterton Suprima 50 Failure

[TrevorG]

Good evening (through chattering teeth). I've had intermittent lockouts on a 3 year old Suprima 50 recently until it finally died yesterday (constant red light). A new PCB has been fitted this evening (by a CORGI fitter) and appears to have lasted 25 minutes, during which time the boiler kept switching off (despite thermostat setting being well above room temperature) & on (every 3 minutes or so) with green light flashing when off. Now it's gone back to a constant red light & turning power off/on, temp control knob up/down, heating control on/off etc has no effect (I've followed the Potterton trouble shooting flow diagram, which leads to "replace Electronic Control": is this a reference to the PCB?).

Naturally I shall phone the fitter in the morning (if I survive the cold) but in the meantime does anyone have any suggestions what has happened? I was a little concerned that the fitter did no checks whatsoever after the first failure and just assumed it was the PCB. Should I insist on other checks given what has now happened? If so, what should they be?

Thanks in anticipation.

 

[ChrisR]

In his defence it's usually the pcb, but there are many other things it can be - fluff in the fan/airways, perhaps. Are you sure it was a new pcb?(yes,= control)

 

[Baxi-Remeha]

the gas valve can take the pcb out, he should check the resistances over the gas valve solenoids.could also be a loose conection somwhere.

 

[TrevorG]

Thanks for the advice. I was told it was a new PCB although they did say it was older stock i.e. not one of the upgraded ones which I understand Potterton have recently brought out.

 

[kevplumb]

had that problem with gas valve solenoid before

 

[ChrisR]

So have I, if you mean a "short" gas valve solenoid popping the fusible resistors on the board. But it wouldn't have been intermittent, which is why I didn't mention it! A short pump can do similar.

 

[kevplumb]

had that one as well
(shuts up and dives for a hole)