Brilliant, on top of everything else in the house needing sorting, now the boiler has an intermittent fault igniting.

Not pressure, seems to be trying to ignite unsuccessful 5 times then error img. Reset doesn’t always work

So how much am I going to have to raid the dwindling piggy bank for?

At a guess, £200? Veritable ecotherm plus not that old and last serviced in March 🙁

Gas pressure okay at the hob?

It seems to be, wifey has said she has noticed burners acting a bit odd recently. Always ok when I test. Off to try again

Hob seems fine all 8 burners light, just retried boiler, failed again. F54 and f28 ignition failure. You can hear the valves opening up and the clicking of the ignition, but it’s not lighting

Is it a pilot light or electric ignition?

If pilot light, is it lit? If electric can you see the spark? (There is usually a little viewing window)

I believe electric ignition, no pilot light I can see. It stopped working last night around the same time but fired up fine this morning when I reset it. it’s odd if a part has failed I’d expect it to be not lighting at all.

Research seems to be pointing to a gas pressure issue, how on earth do you resolve that?

Best I can suggest is to Google about and see if you can find a service manual for the boiler that might tell you what the fault codes are. That may give you a clue whether it is something you can fix yourself (maybe with a suitable replacement part) or something you need an engineer for.

FWIW I’ve fixed my aging Worcester boiler numerous times myself and saved a small fortune in engineer fees. (Though obviously if it is a gas problem then I get the expert in)

Final thought: is the flue clear? Lots of falling leaves this time of year.

Is usually the flue fan switch. In some cases it can be multiple things at once, but let’s start at the cheapest/easiest first! Check the manual for the fault codes. The membrane which actuates the switch perishes over time. It is pulled/pushed when the flue fan moves the air out of the flue as it should.

With the boiler off you can test it by pulling off a vac pipe (there’s two) and gently blow/suck then remove your mouth and you should hear a click, if the membrane is in tact, nothing or it needs a lot of pressure/works intermittently it’s ****.

Not your boiler! but it’s the second part in top left.

Hmm will take a look at the manual, too many glasses of wine for me to take stuff apart tonight, will save that for the morning.

I’ll get up in the loft and check the flue, it’s a long (5m ish) horizontal run which the chap who serviced it commented was odd, but within tolerance. No idea why they didn’t go straight up, or even reuse the old back boiler chimney that’s pretty much next tot the flue….

Another reset, this time with heating off and just trying a hot water tap. Fired up first time, hot water. Not risking fiddling any more tonight. Hopefully I will have heating in the morning. Odd behaviour

My moneys on failing spark plug / electrode.
Might be the air pressure sensor , but as it would appear to wwork when its been off for a few hours then may be the electrode breaking down

Can’t be APS as it is trying to ignite apparently.

Wouldn’t get that far in the ignition sequence if that has failed. Sounds like an electrode problem most likely, but could be PCB or gas related.
Intermittent faults are awkward to deal with and usually point to something electrical.

Can you here it clicking but the gas doesn’t light? If so the problem could be what we had that it was arcing to the wrong spot as some of the flex and protective casing had melted away! A cheap fix to fit some new flex.

it costs £300 for Vaillant to come out and sort your boiler. That covers all parts/labour though.

Either that or a local gas safe plumber!

How old is the boiler?

It worked fine this morning and then has just stopped working again, so after 2-3 of hours use. It’s reset okay after 2 attempts.

Age wise, not sure as we inherited it with the house, would expect it was put in 2012-13 when most of the work was done by previous owner.

How much might those parts mentioned cost? Plus the cost of the callout might be better just to go with valiant….off to google them

Look at the next be off repair from British Gas. Think they do a fixed fee repair.

Just looking at my current provider SSE, fixed price of £150 or £75 if you take out their boiler care policy.

Is there anyway of finding it the age of the boiler? Is there usually a data label somewhere?

Not your boiler! but it’s the second part in top left.

I replaced that in our 30 year old boiler, cost about £15 IIRC and took me about 30 mins.

Spark electrode £8 – £18 depending on make / supplier / availablity.
Bear will confirm this but the usual start up sequence would be
Fan on .- APS Y/N
Purge .- Fan runs for 10 – 20 secs in case of gas leakage into CC
Gas Pressure Check .- Y/N
Open Gas Train ( clicket click ) . . . .
Initiate spark ( Bzzzzzzzzzzz)
Fire in the hole .- wummppphhhh
Flame check.- Y/N ( magic eye / ionisation probe / temp probe)

You should be able to check the electrode yourself . Youtube and Google will show and tell. Look for arcing, missing porcelin , pitting on the point.

Well I’m glad I went with a fixed price, not fixed yet but gas accutator valve and another valve of some description ordered parts in the region of £300 retail…will find out Friday if they sort the ignition issues. Boiler is 5 years old, 1 month out of warranty….

The big negative…the engineer thinks the gas supply pipe is too small a diameter, and has told us the flue is wrong and needs replacing as there is a risk of water condensing and running back into the boiler. It is odd as it runs the width of the house (5m ish) rather than out the nearest wall. Fantastic.

We asked for a quote, he said ‘expensive’ and will let us know on Friday. Any experience of flue replacements what sort of cost should I be bracing myself for?

well no new bike for me in the sales. £500 of materials and 2 guys a morning to replace. just over 1k. ouch. and this was the one thing on the renovation I thought was ok