CORGI visit - queries on regs

[Lobster]

I just has a Corgi round to do a landlord's gas safety certificate. He issued it, but pointed out two minor areas of concern which he says wants sorting - the gas hob needs an isolation valve (which can be in the void behind the built-in oven); and secondly, in said void there is an elbow in the gas pipework with compression fittings, which he wants replaced with a soldered elbow.

I didn't really think about it till after he'd gone; but (a) what's the point of having an isolation valve in an inaccessible location and (b) if there's a problem using compression fittings with gas... don't isolation valves usually have these anyway?

He also pointed out that if I didn't want to fail my electrical inspection, I would need to fit earth bonding across the 5 copper pipes entering and leaving the boiler (which is neither in the bathroom or kitchen). That one's news to me... is he correct, anyone?!

David

[Ed Sirett]

The issue is that the hob requires an isolation valve. I'm not sure what the industry standard category would be if there isn't one. NCS I would think, just possibly AR. See FAQ.

The compression joint is about accessibility it would be poor practice to (say) put one under a wooden floor. My view is that a compression joint behind a built-under oven is OK. If the others in the game read this how would they view things?

I beleive so. This is more about making sure that the CH pipes are bonded to earth than supplementary bonding in a wet location - IIRC.

[BigWallop]

inspection,

If you want to remove the hob, you also need to remove the built-in oven to get at the fixings. So the isolation valve can be in the void at the back of the oven without any fuss, because it's there when you'll need it the most. In a case of a gas leak or severe hob fire, I'd rather everyone turned the mains c*ck off at the meter, rather than trying to isolate each appliance separately.

The earth bonding is needed as part of the electrical safety requirements for the boiler, that's if you or your electrician think it's needed or not. If any faults occur in or around the boiler that could create electrical arcing to the pipework, then the earth bonds are there to try and prevent this happening.

[Lobster]

Thanks for this Ed - checked the FAQ but can't find NCS - wassat then?! (also couldn't find a mention of the need for an isolation valve but as it's your FAQ I'm sure you're right!)

Just seemed to me an odd stipulation if he's *telling* me to fit another compression fitting (ie on the isolation valve) in the same place where he's told me to remove an elbow because it *has* a compression fitting...

David

[ARWadsworth]

He also pointed out that if I didn't want to fail my electrical inspection,

There is usually no reason to bond all the copper pipes that enter/leave the boiler together. Are you sure that the CORGI guy is not asking for the gas supply to be earth bonded?

Adam

[John]

GSIUR 26.6 - No person shall install an appliance without the means to isolate it from the gas supply.

I'd agree with you there Ed. The issue of accessibility is a bit vague here but since its adjacent to a screwed coupling to the hob itself the implication to me at least is that it must be OK

Especially since the use of plastic water carrying parts in many boilers effectively isolates one pipe from another via the boiler so its sensible to ensure that the pipes are equipotentially bonded at this point

[Mike]

But most boilers have a single safety earth connection point. Using this automatically earths the pipes (why 5 ?) so what's the point of adding bonding to each ?

[troubleinstore]

At the last visit of my CORGI engineer, he advised bonding all the copper pipes from the gas boiler. Even wrote on the certificate that the householder would carry out remedial work necessary.

-- troubleinstore Email address in posting is ficticious and is intended as spam trap Personal mail can be sent via website.

my auction items on eBay & eBid:-

[Christian McArdle]

CH Flow, CH Return, Mains water in, DHW out, Gas in?

Alternatively,

CH Flow, CH Return, HWC Flow, HWC Return, Gas in?

Christian.

[Lobster]

Definitely... the gas supply is already properly earth-bonded, which he also checked - he was pointing to the 5 pipes (as identified in Christian's reply) entering/leaving the boiler.

(All but the gas pipe were actually already cross-bonded in the bathroom next door, but that didn't help, apparently!)

David

[fred]

In article , Mike writes

The electrical connection of the pipes by the boiler metalwork is an incidental one which cannot be relied on for safety purposes eg. a fitting may be bolted to a painted case and the fixing normally breaks through the paint but it cannot be guaranteed to. Similarly for electrical links through screwed plumbing connections with sealant applied. The bonding has the sole purpose of being safety electrical connection so it makes a guaranteed connection.

[Lurch]

On Fri, 10 Dec 2004 10:40:53 GMT, "Lobster" strung together this:

He obviously doesn't know what he's on about then. There is no requirement to cross bond the pipes by the boiler.

[Lurch]

On Fri, 10 Dec 2004 16:08:49 GMT, fred strung together this:

What?

[Dave Plowman (News)]

It certainly doesn't make sense to me. If all services are cross bonded at the entry point, and a boiler is earthed by its normal electrical connection, why cross bond pipework at it? And as well as cross bonding, has it got to be run back to the main local earth?

Just curious.

[Mike]

requirements

What are you protecting from what here ? If the pipes make good electrical contact through the (normally brass) compression joints then everything is fine. If there is not a contact then an electrical fault in the boiler will not cause the pipe to become live anyway.

[Coherers]

Wiring regs require main equipotential bonding for the CH pipes, and this "shall be connected to the main earth terminal at the origin of an installation".

If they are not currently, this is probably this is what the Corgi is barking about

[Lurch]

On Fri, 10 Dec 2004 18:28:08 +0000 (GMT), "Dave Plowman (News)" strung together this:

I have worked with some plumbers and electricians who haven't got a clue so just bond everything in sight with 10mm so they've got to be covered. Unfortunately, in most cases they made it worse by mixing equipotential zones.

[Lurch]

On Fri, 10 Dec 2004 19:13:04 GMT, "Coherers" strung together this:

[Coherers]

Wanna bet?

413-02-02

[Dave Plowman (News)]

If so, isn't this unlikely to be at the boiler?

;-)