Keston spark electrode

In article , Andrew Gabriel writes

Was that bitter experience or just a regular FAQ posting :-? Shame on you for not googling and finding my warning on this very subject.

Can't remember where I got mine but think it was one from Keston's recommended list. Seem to remember they were overpriced and I saved quite a bit by blagging trade.

A fixing screw seized & sheared on mine so I have stainless cap screws in place lubed with copaslip.

Bitter experience, but I just searched for and found yours;-) Looks like it happened to Tony Bryer too. It bends easily if heated as decribed above.

I have a theory about the ignition failures described in the original thread...

When it finally locked out at 2:00 in the morning, it appears to have failed to ignite at all, according to my house log, and there are 3.5 minutes between the call for heat and the lockout, so it probably went through its ignition cycle the full 5 times.

It's £15+VAT from HRPC, but it's not a stocked item so they have to order it. I'll get a few other spare parts at the same time... The burner gasket never survives taking the top off the heat exchanger, so I keep a spare one of those, and one of the ignitor gaskets is not quite as good as it was prior to removing the ignitor. I will probably get a spare exhaust tube -- someone here reported one failing, and mine doesn't look as good as it did originally.

Do you remember what size they are? Don't fancy taking it apart again to check, now it's all back togther and working.

After some further strolling around the web, it seems the drooping ignition electrode problem is well known in Kestons, even more so in the larger models.

At least it's very easy to fix, once you know what the symptoms are, and how to avoid breaking the electrode;-)

In article , Andrew Gabriel writes

I've had one ignition failure this year so maybe mine is going that way too or perhaps I need to retest the mix again. I have noticed that sometimes it will start without even a single noticeable click and other times it will take a 2 or 3 loud clicks to get going. The loud clicks suggest to me sparking over at the over-volt gap on the generator pcb but I don't really know whether to treat that as an impending failure or not.

That doesn't sound too bad, either it comes as a kit (including gasket and electrode lead) or the helpful guy at my supplier pointed me in the direction of that when I asked for just the ignitor (igniter?), and sorry no packaging kept to check for the kit part number..

The little envelope that held my spares (now empty at the bottom of the spare screws bin ) is marked M4x8 cap screw, that and the sole tap in my small drills & taps bin is M4 (from cleaning out the threads after drilling the seized screw) make me pretty certain that is the correct size.

Also, re your follow-up on electrode droop, have you seen the Keston section on the gas-news site? I got some useful insights into fixing another boiler there.

Too right

We had both our church boilers serviced by Keston in the summer and I assume that the engineer looked at the igniters and may even have replaced them. A couple of weeks back both had locked out and in each case the short electrode had bent making the gap too wide. Not having any other equipment with me, tapping them against a wall got it back working. I never thought of the gas stove.

This is one of the big minuses of Keston boilers - surely there are enough around for HRPC to keep basic parts like this on the shelf but IME they don't keep any. I waited weeks for a replacement condensate trap (the originals were brittle clear plastic) and in the end wrote to Keston's MD who sent me one gratis.