Problem with CH (Potterton gas boiler not lighting)

[Reckless]

Hiya all,

I've got a Potterton 30F gas boiler in the kitchen which (today of all days!) has gone on the blink. What's happening is that it is trying to start but not lighting. I can hear the fan engage then the microswitch on the Pressure Switch clicks (which I assume is in response to the fan) but maybe it isn't it?! The boiler stays like this for 5 ish seconds then powers down the fan and it does this repeatedly.

It's a tad cold today and I'd appreciate it if someone has some advice on what to look at/replace without having to spend £'s on a call out.

Thanks in advance, Adam

[geoff]

In message , Reckless writes

A potterton WHAT 30F? A bit like saying you have a ford 1600

[Reckless]

Prima 30F

A little bit more info: Blowing/sucking on the tubes from the fan does cause the microswitch to activate. The gas value isn't supplied any power from the control module. Anyone care to guess at what I should check next?

TIA

[Jerry.]

Have you any URL's or other references regarding this matter, PLEASE ?

You can guess who I'll be writing to about the failure of my boilers PCB......

[rob]

circuit boards. My mate at work has had a similar problem, he contacted Corgi(of all people), apparently there is a big court case about this fiasco, as potterton knew they were faulty when they sent them out. My mate got it repaired even out of warranty. Try corgi, ask if they have heard anything. If you have no joy, come back to me, and I'll ask him if I can give his e-mail address, so he can tell you the whole story. rob

remove xxx to reply

[geoff]

In message , Reckless writes

I read what you say, but do you mean that the microswitch is not actually changing over from normally closed to normally open, or that it doesn't cause the pcb to go further through the sequence?

If the microswitch isn't actually changing over when you (gently) suck or blow, then either the diaphragm in the APS is ruptured or the contacts have welded themselves together

If the microswitch is physically changing state, then have the contacts gone high resistance?

If the APS is actually working correctly, then it's the pcb at fault

part no. 407677

The gas valve won't receive any power from the pcb until the APS normally open contacts power the pilot valve/spark circuit

p.s. Please don't top post

[geoff]

In message , rob writes

Do you know which boiler these faulty boards are on ?

[Reckless]

Hiya Geoff,

The microswitch does change from open to closed (or the other way depending on which pipe you blow into!). I can only therefore summise that it's the controller unit that's not working properly. However, it is also fed by some sensors which I guess could have failed?

Cheers, Adam

[Reckless]

Problem now solved. It was a capacitor inside the control unit. Quick visit by an electronics friend, quick examination of the PCB, re-solder a dry joint, swap out the capacitor and the boiler is now working well again. Certainly beats the £90+ for a replacement!

[Jerry.]

Dry joints seem to be something Potterton specialise in it seems... :~(

[geoff]

In message , Jerry. writes

They're not technically dry joints, they're cracked joints due to crap flow soldering

[rob]

sorry about the delay in coming back to the group, have had permission from mate to offload e-mail address to those interested in the potterton fiasco, and the problems with the pcb boards in them. if you mail to [e-mail] he will explain , what the problems are, who he talked to and who sorted the problems out etc, he will tell you how corgi and trading standards got involved rob