earthing boiler pipes

[sandancer]

I had a survey done with a view to having my combi boiler replaced when the question earth bonding came up.

The surveyor informed me that the pipes going into the unit would have to be bonded.

I have read a recent post by johnD that there is no reg. that says this must be done and I fully accept this as fact.

However, since this is the way the man says it has to be done then so be it. so in the absence of any earth bonding cable in the vicinity I am going to run a cable in preparation.

The thing I need to know is if 6mm cable woul be ok or does it have to be 10 mm.

My main earthing is from a pme system.

 

[bongos]

The surveyor informed me that the pipes going into the unit would have to be bonded.

I'm ready to be scolded here...

But I think that bonding all pipes together at the boiler may actually be a requirement of the gas regs. As JohnD stated it is not a requirement of the electrical regs.

 

[Taylortwocities]

I assume that the main bonding to water and gas/oil etc is in place?

In that case there is absolutely no need to bond the pipes to a boiler. Even if there was, the copper pipes all come together and are fixed to a nice metal plate under the boiler which would effectively bond them.

He is smoking out of his rear end. Have him show you in BS7671 where it says this is necessary.

If you really must waste money (and the World's copper resources) then you can cross connect each with the pipes with 4mm earth sleeved cable.
Each pipe will need a BS951 clamp.
DO NOT run this earth cable back to the fuseboard.
You are cross bonding NOT earthing.

But as I say, its a waste of time and money and not needed.

 

[londonboy]

Although a waste of time, most installers still insist on this. Probably to cover their back incase any pipework became live etc etc. As said above no need to take bonding back to ccu. They may just link the pipes, or link the pipes and take back to a local supply (boiler spur).

 

[superlec]

DEAR SANDANCER. THE EARTHING REQUIRED IS CALLED EQUIPOTENTAIL WHERE AN EARTH CABLE NEEDS TO BE CONNECTED / LINKED TO THE FLOW +RETURN,DOMESTIC HOT WATER,COLD WATER FEED, AND THE GAS FEED PIPE AND THE CHASSIS / EXPOSED METALWORK/EARTH POINT OF THE BOILER.THIS WILL HELP WITH ANY POTENTAIL VOLTAGE FAULT TOO ANY OF THE METAL PIPEWORK WITHIN THE WATER/GAS/AND HEATING OF THE INSTALLATION.

 

[kevindgas]

DEAR SANDANCER. THE EARTHING REQUIRED IS CALLED EQUIPOTENTAIL WHERE AN EARTH CABLE NEEDS TO BE CONNECTED / LINKED TO THE FLOW +RETURN,DOMESTIC HOT WATER,COLD WATER FEED, AND THE GAS FEED PIPE AND THE CHASSIS / EXPOSED METALWORK/EARTH POINT OF THE BOILER.THIS WILL HELP WITH ANY POTENTAIL VOLTAGE FAULT TOO ANY OF THE METAL PIPEWORK WITHIN THE WATER/GAS/AND HEATING OF THE INSTALLATION.

stop shouting

under the old rules it was expected to cross bond, but new regulations(17th Edition) relies on Rcd protection and has moved away from cross bonds

personally i still believe bonding to be the safer option, even with the new 30Ma Rcd's (this is my choice not regulation)

 

[Spark123]

Now you are mixing up the requirements for supplementary equipotential bonding in a location containing a bathtub or shower basin with the non existent requirement to supplementary bond the pipework for a boiler, (unless of course the MI specifies it.)

Under the 17th edn regs, under certain conditions the supplementary bonding in a location containing a bathtub or shower basin may be omitted, however if those conditions for that location are not met then supplementary bonding is still required.

 

[superlec]

dear all . i had no idea about caps meant shouting,no offence intended ,not been onboard long only writen a few replies since joining in january this year.once again no affence meant. superlec.

 

[Spark123]

You're allowed to use capital letters to start sentences and names tho

 

[gas4you]

I was only thinking about this whilst earthing all the pipes on a combi installation I was finishing off this afternoon.

No need for me to ask now

I tend to still do this on each job, but has it only not been necessary since the 17th came in?

There is nothing in our gas regs stating it has to be done.

 

[RF Lighting]

Nope, it was not required under the 16th edition either.

Perhaps it hails back to the 15th edition along with kitchen sinks etc?

Maybe one of the old boys can say for sure?

 

[conny]

Ahem, I think the term 'senior boys' or more 'mature members' would be more politically correct these days.



BTW, it was the method in the 14th if that helps.

 

[kevindgas]

BTW, it was the method in the 14th if that helps.

just goes to show how old habits die hard. as said previously I still prefer it even if its old hat

 

[securespark]

Nope, it was not required under the 16th edition either.

Perhaps it hails back to the 15th edition along with kitchen sinks etc?

Maybe one of the old boys can say for sure?

As a semi-old boy ( ), as far as I recollect, there was no requirement in the 15th to supplementary bond at a boiler. However, I do remember when I was an apprentice, my boss getting all hot under his collar about supplementary in the airing cupboard, where all pipes were bonded together, along with the cpc of the immersion circuit.

I think, as has been said before, that the bonding at boilers is a gas regs requirement.

Supplementary in kitchens was a requirement under the 15th, but was deleted from the 16th.

Any proper old boys prepared to comment?

 

[bernardgreen]

Going back 40 years.

The reason to electrically bond all pipes at the boiler was to prevent any chance of a spark between pipes which, in the event of a gas leak, could cause an explosion.

In those days boilers were built very differently. Few if any boilers had internal pipe work bringing all the pipe connections onto single plate. The water pipes had to be plumbed directly into the heat exchange and these connections could be a foot or more apart on a cast iron block.

Modern boilers with all connections to the single plate effectively bond all pipes via that plate.