Baxi Combi 105e igniter(?) issue

SpiderKenny · Oct 28, 2011

I have a Baxi Combi 105e with what appears to be an igniter issue. I'd appreciate any help or advice anyone has.

The problem originally was that the boiler would simply not light. It would go through all the stages, then eventually just stop with the 'Flame Failure' lamp lit.

I eyeballed the boiler and could see that there was no spark.

I followed the Fault Finding process in the service book and ended up at section H, when I metered out pins 3 & 5 of A1 on the main PCB sure enough there was only about 80VAC present, not 230. I replaced the PCB with a brand new one from PlumbCentre and immediately the boiler started working and it worked perfectly for 3 days.

Now it has gone back to the original fault. If I reset the boiler then occaisionally it will start and run for a while, but after a couple of hours or so it goes back to Flame Failure.

Any suggestions?
-Kenny

.ps. After resetting it does this, which I think is normal....
1. The fan runs for a few seconds then stops.
2. The fan and Pump run for a few seconds, then there is a click and then it either lights or goes to flame failure.

peteisfishing · Oct 28, 2011

I have come accross similar prob before albeit on a different boiler, turned out to be the air pressure switch. Ensure all air pressure hoses are clear, if so put in a new switch and see if that helps. My fault was intemittant to

moogwai · Oct 28, 2011

Yep.....aps

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SpiderKenny · Oct 28, 2011

Thanks guys, I'll check it out.

craig gas · Oct 28, 2011

aps switch unlikely as this fault would not illuminate the flame failure light the fan/flue light would identify an aps fault on the 105e

fixter1 · Oct 28, 2011

can you see if the boiler is sparking at all before it locks out or is there no spark at all,, if no spark it points to aps fault

SpiderKenny · Nov 1, 2011

This was definitely the igniter as it turns out.
Here's what transpired....
This boiler had an igniter which was screwed to the front of the gas valve - a small square black one.
There was no spark - but the boiler did go through the full start up procedure, the gas valve was opening and gas was entering the burner. I believe an APS fault would have stopped the sequence earlier. Even so, I took the advice and checked out the APS and it's tubes and it all seemed perfectly OK.

I replaced the igniter and everything was back to normal.