Glow-worm Ultimate 40FF electrode continously sparking

[namsag]

In defense of DP by his replies on the the forum in general he is definetly not a parts changer and is someone who will thourghly investigate a problem and repair it with no unnecassary parts. But his reply does suprise me.
I do agree pilot can be light without the proper signal going back to the board.
Small amount of gas lights but because it is too weak to heat electrode properly board keeps sparking and heating it with a lighter/match or weak b/lamp will confirm this by sparking stopping and main burner coming on.

But as it was working ok before he messed with electrics my first check as i have already said would be the polarity

 

[geoff@cetltd]

My heating fault?

Thanks in advance!

Everyone seems to have missed the fact that the HT lead might have broken (at one of the connecters). This would not stop it sparking, but it could prevent flame sensing

sorry, no time for CORGI bashing today

 

[namsag]

Looks like you have no time for reading either as gas4you suggest that on saturday

 

[geoff@cetltd]

Looks like you have no time for reading either as gas4you suggest that on saturday

looks like it ...

 

[DP]

Namsag, I have been embarrassed by this boiler in the past. I had a call from a client (who got my name from a friend of his) to take on the job of repairing the Ultimate that continued sparking with no flame at pilot burner. As the call was “beyond” the boundary of operation, I took with me a PCB, fan and a gas valve.

With the combustion chamber cover off I was looking at a pink spark discharging from the electrode to the burner. This fact was registering in my brain but not opening the memory door as I had come across this coloured spark before (answer to colouring end of post). In frustration and brain not in gear, I changed the gas valve and then the PCB. Fan was never changed as the APS was operating to initiate ignition sequence. Original parts were refitted with new parts put back into stock for when and where these would be needed.

Around this moment client’s neighbour stuck his head through the door to say the pilot injector could be dirty. This was the moment the pink tint on the spark made sense. When gas is present but below LEL, blue spark takes on a tint. No gas would have resulted in blue spark. I was mortified by my stupidity that day. Needless to say, I made a token charge for the callout and none for time spent on site.

This pink tint spark on another occasion had me remove the burner assembly to take out a floral foreign body from the burner bar that had spark from electrode discharging on it (Ariston microgenus). On a Vokera Option, loose injector feeding gas into burner blade was also exhibiting same symptoms. Both boiler were failing ign lockout at random.

 

[bones001]

Small amount of gas lights but because it is too weak to heat electrode properly board keeps sparking and heating it with a lighter/match or weak b/lamp will confirm this by sparking stopping and main burner coming on.

as you know i have been following this post and hope it ends now but i had to just comment on the heating of the probe. The rectification does not work by heating the probe it works by the ionization of the outer cone of the flame being able to conduct electricity which in turn turns AC into DC and something to do with less electrons going back to the board than its sending out makes it realise there is a flame i think, but yes there needs to be a big enough flame to conduct the electricity through it and that was my point, add a bigger flame just to check this. it just got a bit out of hand. no doubt the next post underneath this one will be the OP saying they have decided to have the boiler replaced and we will never know what the real problem was

 

[namsag]

Bones you seem to be missing the most basic point here and that it is a DIY site and people need things explained in basic laymans terms not how the laws of chemistry and physics would explain it .
So there is absolutley no point trying to look a smart ass as the diyer would be completely lost . First rule of fault finding keep it simple

 

[croydoncorgi]

Well....
HAS the OP actually checked the polarity yet?
Given the sequence of working boiler, electrical component and wiring changes, followed by non-working boiler, I'd have thought it was a racing certainty!