Boiler Not Igniting

Joined
17 Oct 2010
Messages
9
Reaction score
0
Location
Derbyshire
Country
United Kingdom
Hi All

I'm hoping someone can help diagnose an issue we're having with our Potterton Suprima boiler as I've not been able to figure out what the issue is after a day of troubleshooting and investigation.

Its probably worth mentioning that we had the PCB replaced about 18 months\2 years ago. The thermostat is calling for heat and the temperature on the boiler is set just below Max.

When there is no call for heat there is a solid amber light.
When there is call for heat from the programmer there is a slow flashing amber light (off 1 sec, on 3 secs).
Nothing then happens, the boiler does not try to ignite

After a period of time, sometimes 5 minutes, sometimes an hour - the boiler will try to ignite, there is a green and amber flashing light, the fan will kick in, there's a couple of clicks but the flame doesn't actually ignite and goes back to a slow amber flashing light. After a bit of time it will try to ignite again but fail.

Sometimes though, it does ignite - this morning it was running fine for a few hours but now it doesn't want to ignite at all.

The 3 way valve seems to be working OK, I can manually open it.

The pump seems to work fine when it was running this morning.

We changed the igniter lead for one that we knew was working but this made no difference. We also checked the diaphragm valve with a multi-meter and this seems to be working OK when there was a vacuum.

It is the same when trying to turn on CH or HW.

Has anyone experienced this before that could offer any suggestion of what the cause might be?

Thanks in advance

Steve
 
Have you checked the thermistor, if not that then likely to be PCB.
This work should be carried out by a gas safe engineer.
 
Just to close the loop on this one.....

I got a replacement PCB, fitted it and it started first time and has been successfully working since.

That's the second replacement PCB I've had to pay out for now, the first replacement lasted about 18-24 months - if it happens a third time I think I'll be seriously considering a replacement boiler.

Thanks

Steve
 
Back
Top