Servicing your own gas boiler

Not necessarily even evidence. The house might have blown up for reasons which had nothing to do with the boiler.

In article , Onetap scribeth thus

What makes you say that, are you a Gas safe fitter at all?..

How would anyone?..

Well he can measure the CO 2 output etc but as to the board there are other bits it does which might get missed and if an intermittent fault?..

In article , Onetap scribeth thus

Well competence isn't quite the matter here. For a start matey here replaced the whole boiler which is taking the piss a bit;! and didn't have the annual inspection cert which a landlord must have,...

Well just as well with those things!!. Still our Geoff does well re- furbed ones...

No. I don't fit or service gas appliances, so it's not relevant to me. I have had to study various gas documents over the past 20 years and know a fair bit about gas.

I'm certain he's mistaken.

Flue Gas analyser and the relevnat training course in its use.

We've moved on from the competent or approved discussion.

Landlords are specifically covered by Part F of the regulations and can only legally have gas work done by an approved (Gas Safe) person, regardless of how competent they may be.

He did replace the boiler. The conviction was for the parts of the regulations requiring competence and being a landlord & having a non-approved person doing gas work. He would have been equally guilty if he'd just replaced, say, a PCB.

... whereas my old glow-worm runs the case at positive pressure. It sucks fresh air in with a fan, this then goes past the burner and the heat exchanger on the way out. The parts in contact with the room only have fresh air.

I've been told this is dangerous, but never why. I can't see how, as a leak would just result in a supply of cold fresh air into the house.

Andy

If it really *is* like that (and I'm not convinced that you're describing the operation of the fan correctly!) the reason it's dangerous is that, if there's a problem with the seals on the combustion chamber, the products of combustion - including CO - will leak into the room.

Most boilers have the fan blowing the products of combustion *out* through the flue, so that the combustion chamber is at below atmospheric pressure. Then, if the seals leak, air from the room will be drawn *in* rather than nasty stuff coming *out*.

You do understand that the original statement was re the "gas path" don't you?..

Have you got the specific part of the regulations that covers that?..

I think you took that out of context .. never mind..

Gas train; the PCB controls operation of the gas valve, fan, ignition, burner, etc., and so is a critical part of the gas system.

He's mistaken. I won't be searching the gas legislation to prove my point.

More liable to become dangerous than conventional boilers. A perforated case, due to rust, and a partial obstruction of the flue could allow fumes into the house.

Most work at negative pressure so that leaks go into the boiler. Fume cupboards work on the same principle.

A perforated case due to rust _AND_ a partial obstruction of the flue could... do nothing of the sort. No part of the boiler containing flue gasses is exposed to any part of the casing that is exposed to the inside air. Even the exhaust is concentric (if that's the right term, when it's square).

Think of it like a Haber Process vessel.

Andy

In article , Onetap scribeth thus

Well please yourself but this man does this day in and day out and has been doing so for a long time so!...

And you just read the regs and interpret them as you will;?..

How do you get to the inside of the combustion chamber to clean it out when it needs servicing? Presumably it separates into two parts, with a seal between the two? What if that seal fails? If the combustion chamber runs at above atmospheric pressure, the products of combustion will come

A failure of the casing seal would let fresh air from the pressurised outer casing into the room. You have to take the entire casing off to service it - and incidentally, this makes diagnosis a pain because when you do the pressure switch notices, and it won't even light the pilot.

Andy

There's not a high level of technical understanding required of the Gas Safe qualifications. They just have to be able to service or install gas appliances safely.

I've given reason for my opinion above. It's not something that is open to misinterpretation; the PCB controls the combustion process. I read something about this years ago and don't recall where.

You interpret them as you will. I don't give a stuff.

You think so? It's under positive pressure.

Which this one does and very well too on a day to day basis ..

Beano perhaps?..

Me neither....

You're a nasty little thing, aren't you.

I am profoundly sorry that my opinion doesn't correspond with what you'd like to hear.

If you remain in any doubt about it, why don't you post the query on the DIYnot forum, where several Gas safe types will give you the benefit of their opinion.

That is here;