Baxi 105e intermittent flame (with a twist?)

[gj71]

I have a Baxi 105e about 5 years old, the pcb was replaced about 5 months ago following its complete failure, and everything has been fine until the last few weeks, the boiler now only works when it wants, theres no pattern, whether its warm or cold, been used minutes earlier or not. It does the same for the dhw and ch. Now for the strange part, whenever the front panel is removed (just the front panel) it works fine, I left the panel off for a few days and everything worked fine, so put cover back on and within hours it had failed again, now either this is a huge coincidence or removing the panel has some effect, have checked for loose connections bad earths etc and nothing. I am confused as to how removing the front panel could allow the boiler to work.

Thanks
G

 

[namsag]

By front panel you mean just the big white cover ?

 

[gj71]

I do yes, the boiler cover not the internal flame cover

 

[spacethegas]

odd

 

[twgas]

what exactly does the boiler do when you run the hot tap - does it make any noise, lock-out etc

 

[namsag]

Very odd as nothing touches this and it seals nothing

When the cover is off do you have the contol panel hanging down or is that still in correct position.
If its hanging down i have had faulty boards work like that but not in the correct position.

 

[gj71]

what exactly does the boiler do when you run the hot tap - does it make any noise, lock-out etc

When it dosnt work the boiler starts as normal you can hear the clicking of the electrode as normal but you dont get that rushing sound of the gas igniting, so this seems to be the failing point.

With regard to the control panel, it dosnt seem to matter up or down, I thought it could be bad connection/earth but now dont. As far as i can tell nothing comes into contact with the front panel although without xray vision cant say for defo! but no dints in front cover or body of boiler and the spark generator is the foremost part and sparking dosnt seem to be the issue.

The only thing I can think removing the front panel does is allow additional ventilation?

 

[gas4you]

The only thing I can think removing the front panel does is allow additional ventilation?

Only the internal combustion chamber door is sealed, not the outer case.

 

[gj71]

Only the internal combustion chamber door is sealed, not the outer case.[/quote]

I know, which is what makes it all the more strange?

 

[gj71]

Just to confirm my thoughts I left the cover off all last night and no problems, messed about switching ch and dhw at different times during the evening, all ok. I then replaced the cover and it worked until this morning when I ran the shower and once again wouldnt ignite, removed cover and hey presto worked again, I am so confused!!!!!!

 

[ChrisR]

This is elvish. Do you mean you leave off just the "Case front panel?"

 

[Kev F]

have you checked that when the case is on its not trapping wires etc

 

[Agile]

If I discovered that I would measure for any voltages between the parts the cover touches.

If that yielded no clues, then I would be pushing and pulling everything that the cover contacts.

Tony

 

[diverdee]

watching this one with interest. hope it is the boiler cover he taking off !!

 

[gj71]

Sorry first chance I have had to post again, it is the case front panel as you see being removed in the diagram, there are no trapped wires, I have removed and repaced any connections, earths and pcb block connectors, still havnt put the front cover back on and no problems, I even tested the ch on timed and came on, have checked pressure switch and seems ok with a gentle blow/suck, fans comes on as normal. I have now come the end of my basic abilities, so will ask a freind who Corgi registered (who on his hols at the moment), he will look it over and see if theres any faulty parts, will let you know my findings (if there are any!!).