Sime Friendly Format 80E - flame cuts out intermittently

[Geoff123]

Hi, I hope someone can give me some advice.

My boiler cuts out after it has been on for a while. Initially it ignites perfectly, with both hot-water and also central heating. However, after a while the flame cuts out. The flame will remain out until I turn the boiler off and on again, when it usually re-ignites.

This has been going on for about a year now and it has been getting progressively worse. Now the flame cuts out sooner and it will not re-ignite unless you leave the boiler off for at least an hour.

I have had a plumber look at it, and when he first removed the front cover, and turned the boiler on, the flame ignited and stayed on for ages. Furthermore, after he did this the boiler worked perfectly for about a week. Then it returned to it's old tricks again.

I got him back and he thought that it was the air pressure switch, changing which has had no effect at all. His other idea is that the fan is faulty.

I am skeptical about his suggestion as the fan appears to be blowing out well, and starts up every time, and remains on after the flame cuts out.

Has anyone got any ideas?

 

[lagunaglen]

I doubt its a fan problem as when the fan goes on these it blows the fuse on the pcb.
it seems more likely that its overheating, is the pump noisy,or does it feel excessively hot to touch?

 

[undercover]

more than likely the ignition pcb needs replacing.

 

[Geoff123]

Thanks for your replies!

I don't think the plumbing is unusually noisy. There are not air locks or gurgling noises if that is what you are thinking.

The hot-water does get unusually hot initially, before the temperature settles to the target. Perhaps it is overheating as you suggested?

However, once it has cut out once, the flame will not ignite unless I leave it for about an hour or more, even though the water flowing through the boiler is cold...