Combi Boiler

neilmcl

How can a combi boiler have a completely sealed combustion chamber via it's casing when there's open access at the bottom for getting access to the filling loop for example? Also, I've never seen seals on WB combis.

Jeepers_Creepers

neilmcl said:

How can a combi boiler have a completely sealed combustion chamber via it's casing when there's open access at the bottom for getting access to the filling loop for example? Also, I've never seen seals on WB combis.

Mine is a 16-year old GlowWorm. There's the outer front decorative cover - which clearly has no bearing on gas seals - and ditto for the boiler sides - they pop off easily to give access to all the 'wet' and electrical stuff.

Inside there's a secondary cover which is 'sealed', although to a generally perfunctory standard. It's secured with two screws, has a foam strip around it, and the pipes which pass from this compartment to the lower 'outside' part of the boiler pass through rubber grommets. These are all 'low-key' seals, and unlikely to be fully airtight (eg where the pipes pass through the grommets).

I think the idea is that the fanned air intake to the 'proper' combustion chamber (further inside again) is taken from this sealed-off area, and obviously most of the air is drawn in from the outside flue pipe. But this chamber is probably at a gentle negative pressure as a result of this sucking, so that if any combustion leaks were to develop around the 'engine', then they'd be caught and disposed off without going any further.

I have to say I am personally happy to remove this internal cover to gain access to things like the top of the condensate trap and to undo the flow/return pipe from the main exchanger when swapping the Hydroblocks, for instance, but would not suggest anyone else do so.

I never have, and never would, go further - the gas valve, fan, combustion chamber etc.

thorganby

Jeepers_Creepers said:

neilmcl said:

How can a combi boiler have a completely sealed combustion chamber via it's casing when there's open access at the bottom for getting access to the filling loop for example? Also, I've never seen seals on WB combis.

Mine is a 16-year old GlowWorm. There's the outer front decorative cover - which clearly has no bearing on gas seals - and ditto for the boiler sides - they pop off easily to give access to all the 'wet' and electrical stuff.

Inside there's a secondary cover which is 'sealed', although to a generally perfunctory standard. It's secured with two screws, has a foam strip around it, and the pipes which pass from this compartment to the lower 'outside' part of the boiler pass through rubber grommets. These are all 'low-key' seals, and unlikely to be fully airtight (eg where the pipes pass through the grommets).

I think the idea is that the fanned air intake to the 'proper' combustion chamber (further inside again) is taken from this sealed-off area, and obviously most of the air is drawn in from the outside flue pipe. But this chamber is probably at a gentle negative pressure as a result of this sucking, so that if any combustion leaks were to develop around the 'engine', then they'd be caught and disposed off without going any further.

I have to say I am personally happy to remove this internal cover to gain access to things like the top of the condensate trap and to undo the flow/return pipe from the main exchanger when swapping the Hydroblocks, for instance, but would not suggest anyone else do so.

I never have, and never would, go further - the gas valve, fan, combustion chamber etc.

Don't worry Jeepers, not all GSR's are so sniffy about what we can and can't do to our own boilers e.g.https://www.assettplumbing.co.uk/can-you-service-your-boiler-yourself.

This is a money saving site and it is hard to follow advice from anyone who first response is you need a GSR without knowing what the problem is, followed by you can't take the cover off.

When was anyone prosecuted for checking/recharging their own expansion vessel?

What do the Gas Safe Register do when they are informed that one of their members has broken manufacturers installation rules, done a very poor job etc., not a lot as they are a paid up member of the thou shall not club!

Jeepers_Creepers

That link to assettplumbing is interesting!

I do take on board what Fez says, 'cos I have no way of judging the ability of anyone who comes on here asking for advice.

With the other thread - now deleted... - the OP had already carried out the bulk of the work, replacing the screwed-in sensor, and just need a leg over the hurdle of what to do about the corroded plug. On balance, that was an easy one to help with.

Hey-ho. Each one on its merit

fezster

Jeepers_Creepers said:

That link to assettplumbing is interesting!

I do take on board what Fez says, 'cos I have no way of judging the ability of anyone who comes on here asking for advice.

With the other thread - now deleted... - the OP had already carried out the bulk of the work, replacing the screwed-in sensor, and just need a leg over the hurdle of what to do about the corroded plug. On balance, that was an easy one to help with.

Hey-ho. Each one on its merit

Just to clarify my position. 

Whilst I technically agree with what is or is not permitted in law, I do find it aggravating when standard responses are "call a professional". It makes sense when something is quite clearly in the realms of gas and should not be touched. However, for expansion vessels and pressure reducing valves (just 2 examples which come up often), there's an element of pragmatism on giving advice. Depending on whether the EV is inside a combustion chamber or not and depending on whether the prv is on an unvented cylinder, it can be permissible or not.

Depending on how someone has asked the question, they'll either get good advice or they'll get a blanket "not allowed". What's absurd is if the person signs up with a different account and asks the question in a slightly different manner, the advice will be given without hesitation.

IMO, it'd be far more sensible to give the good advice but caveat it with what is permissible or not. Its then up to the poster to decide how to proceed. 

Ibrahim5

I was listening to a gas installer in the sauna at the gym. He was boasting that he and a friend installed combis for £1k profit in less than a day. His mate who wasn't registered fitted them and got £500. He did the paperwork and got £500. I was thinking it's OK for people who aren't registered to do gas work when it suits the RGI.

Jeepers_Creepers

Ibrahim5 said:

I was listening to a gas installer in the sauna at the gym. He was boasting that he and a friend installed combis for £1k profit in less than a day. His mate who wasn't registered fitted them and got £500. He did the paperwork and got £500. I was thinking it's OK for people who aren't registered to do gas work when it suits the RGI.

I understand that is definitely breaking the law.

southcoastrgi

You have to be competent, to work on the gas or flue side of a boiler you must be GSR, work is classed as something you get paid for, if you don't get paid for it ie it's your own boiler then it's not classed as work, should anything go wrong & it ended up in court you would have to prove how you are competent if not GSR, is it right no of course not but that's how it is.

OP take out BG cover & live with it for 6 weeks then report loss of pressure 

Jeepers_Creepers

southcoastrgi said:

it's your own boiler then it's not classed as work, should anything go wrong & it ended up in court you would have to prove how you are competent if not GSR,

I think that would prove itself by the cause of something having gone wrong.

If you left a gas connection leaking or a flue pipe loose, then clearly you aren't competent - and you are totally liable (GSR or no). If, however, you did everything by the book and there was no error in the installation, then clearly the installation was 'competently' carried out. If something subsequently went 'wrong', it wouldn't have been the installer's fault, GSR or no.

southcoastrgi

But sometimes you can't tell what the issue is for example a gas explosion, the investigation can pin point the area but it may prove difficult to say the exact reason, depending on the issue a RGI might be prosecuted for negligence if someone died whereas a home owner that has DIY'd it could be done for manslaughter