Non working boiler, PCB replacement

Thanks, John! Hope you have replaced the failing cap and now have a spare PCB?

Alas no, it was a "recon exchange" PCB - so you need to send the dead one back. (but has the advantage of only being ~£65)

Still the first one lasted 10 years - so I ma hoping to not need another soon!

We had a frozen condensate pipe.

Fortunately we have a service contract- and several fan heaters to use while waiting.

The chap was able to dry the burner etc out - there was a surprising amount of water which had leaked out onto the garage floor, soaked the burner, etc.

Seems ok now.

My boiler is a Vaillant Ecotec 415. I have a spare PCB, display, buttons, etc., simply because the boiler failed last year and I ordered a used control unit from Ebay. However, before it arrived, I took the old one out to see how difficult it was and temporarily re-installed it

- only to find that it must have been a dodgy connection as that started it working again and there have been no problems since!

In message <tnnesm$dp9$ snipped-for-privacy@dont-email.me, John Rumm snipped-for-privacy@nowhere.null writes

Mine on my Sime Boiler went TU in my static caravan in November. The plumber got a cheap replacement off e-bay. I wasn't in the position to fix it myself, but he left the dead board and I could see a capacitor had blown - bulgy top and leaked electrolyte . The fuse had gone g'bangy, so the tracking from the electrolyte might have taken something else. I might try replacing the capacitor and cleaning the board. There's a switch mode supply to make 24V. It uses a standard chip and circuit straight off the data sheet.

One thing the plumber said it would need calibrating for LPG and he had no reply from Sime by the time I went back down to get it ready for winter However I'd spotted it in the installation manual. So all working again, which was just as well as it was -6C when I was there.

Brian

Capacitors do seem very vulnerable to premature failure on all sorts of electronic stuff. Many older VCRs used to file as these went low value in the psu, and I've heard the effect of this in stereos and seen erratic behaviour in tvs, internet routers and many other things. I just don't think manufacturers realise how such devices can age. They buy cheap as they seem to work just as well when new, but then fail after a couple of years service. Brian

When I first subscribed to this group there were several postings about the faulty pcbs on Potterton Suprima boilers, and I'd just had one of those installed. But when it failed a few years later I knew exactly what the cause was and how to fix it. No problems since.

You're not the only one.

My nephew's boiler died. As it cooled down the temperature change finished off the cylinder, and that started leaking :(

(He's gone for an unvented cylinder, partly on my advice, and he luckily has an old school friend who does these things.)

Unfortunate that he's just written his car off too!

Andy

Those of you on here 20+ years ago may recall I installed a Keston Celcius 25 slightly before Part L which made them mandatory. Ed Serret had one too at around the same time.

These were early domestic condensing boilers, but at the time, they did have stainless steel heat exchangers unlike others on the market which were aluminium and didn't last long. Keston came to domestic condensing boilers from having manufactured large commercial condensing boilers for years, whereas the other domestic condensing boilers at the time from the better known domestic manufacturers were modified from their non-condensing counterparts and not at all reliable.

Anyway, the Keston has run well for years. It could heat the house running at 45/35 flow/return, so it hasn't been hammered hard (and it doesn't do the hot water, which is handled by a separate multipoint instant water heater). Of late, it's had a problem relighting when warm, and I've had a hint that's likely to be a dirty gas valve. (I can see the gas supply has been dirty as there's noticeable levels of dirt in the gas supply pipe.)

However, more recently, the system had started losing pressure, having never lost anything for 20 years. My instinct was to suspect my plumbing (the whole central heating system was installed from scratch by me), but I couldn't find a leak, and losing a litre of water would surely leave a noticeable damp patch somewhere. Eventually I thought could it be the heat exchanger? Rerouted the condensate drain into a container, repressurised the system (which wasn't running at this time), and sure enough, drips from the condensate drain. Damn!

Around 10 years ago, I bought another Celicius 25 for spares which another member here was chucking out after losing confidence in it. British Gas had been maintaining it but failed to keep it running reliably. (It was in a terrible mess inside due to leaking condensate and leaking auto bleed valve, which eventually corroded through the casing.) Much of the guts had been replaced so it wasn't as old as it looked at first glance. It even came with the new case BG had ordered still boxed up, but the owner just wanted shot of it by then. Anyway, I wasn't impressed with how BG had maintained it. Mine still looks brand new inside, but that's only because I tackled and fixed a condensate leak due to a manufacturing fault very promptly.

This enabled me to transfer the new heat exchanger across, and get mine working again. I had to fix the thermal mat wrapping it which had completely fallen off (again, must have been poor maintenance - there's no reason for that to happen). However, my boiler is now working again and holding pressure.

The failure to relight when warm persists, but actually it rarely attempts to do this, so it hasn't caused a lockout for weeks now. I probably need to pluck up courage and dismantle and clean the modulating gas valve, but I have visions of pingfuckits shooting in all directions, and no instructions for any calibration post reassembly, and replacements are no longer available.

Andrew

Yup pretty much what happened to mine about three years ago. (see top half of that wiki page!)

The place I got my recon HX has some Keston bits normally: