Ignition rod sparking in wrong place

[chrisw99]

The saga with my aging Halstead Best 50 continues, but not for long. Got lots of independents coming this week to give me quotes for a boiler replacement as I've finally had enough. So this is a theoretical question as I'm almost certainly not going to bother fixing it...

Had someone in to have a look at the latest cause of the occasional ignition lockout.

95% of the time, the ignition rod sparks at the tip where it is supposed to do. The other 5% of the time, the sparks happen at the base of the ceramic rod across to the base of the burner.

Chap recommended replacing the ignition rod/cable and possibly the PCB, both of which were replaced just 3-4 months ago so should be brand new, hence my having had enough, this boiler has to go.

I really don't want to spend another penny on this now... I could possibly live with getting him to replace the relatively cheap ignition cable, but not unless I'm sure that will fix it 100%.

What could cause a brand new ignition cable/rod to be sparking at the base rather than the tip? Could I have just been unlucky and got a faulty one?

 

[Madrab]

Usually down to gap setting or dirt/rust around the vicinity of the electrode. Ignition spark will take the path of least resistance so if it can find a narrower gap elsewhere that it can jump then that's where it'll go.

 

[chrisw99]

Cheers, nice and simple explanation. Still, had enough with this one now so it's time for a new one.

 

[Gasguru]

Halstead have some of the cheapest nastiest electrodes going....I've had several where the wire has become detached from the electrode inside the ceramic (poor welding).
Looking at the parts list it would appear that some of the Best electrodes have a glass fibre sleeving over the wire and ceramic....perhaps that was to alleviate the problems you have.

 

[chrisw99]

Interesting.. Yes there was a glass fibre sleeve over the wire, but the flame sensor wire has also been put through this sleeve which means because they diverge (flame sensor at back, igniter at the front) the cables are bare again for the few inches up to the ceramic rods. Maybe the flame sensor cable didn't need protecting, so the sleeving should really be solely on the igniter all the way up and including the rod.