Copper pipe, plastic push-fit to Radiator - earthing/bonding

[diychicken]

Hi all,

I've seen the //www.diynot.com/forums/viewtopic.php?t=20167 thread was posted a few years ago so I wanted to check again in case things have changed and specify my own situation.

I have installed a new chrome towel radiator in my ensuite and am trying to figure out how / if I need to earth it.

The original piping and earth bonding looked something like:

(R = radiator; E=earth bonding; C=copper fitting; -=copper pipe)

[code:1]
R
|
E
|
|
----C----C----C----
[/code:1]


To re-site the radiator I had to re-plumb and used plastic pushfit connectors with copper pipe. So the piping on each side of the radiator looks something like:

(R = radiator; P=plastic pushfit fitting; -=copper pipe)

[code:1]
R
|
|
P
|
----P----P----P----
[/code:1]

So, my question is, do I need to put an earth bonding on the pipe at the same place as the original installation, or do I not need it, or do I need it at the last place on the pipe before the first plastic fitting? Or something else totally?

Also, does the earth bonding tag need to be above the floor or can it be below the floor (tidier)?

Many thanks.

 

[Spark123]

Yuk . Short lenghts of plastic don't afford adequate isolation so the radiator will still be an extranous conductive part. That means that the pipework which is making the radiator extraneous requires supplementary bonding.
I take it you have all this x2 for flow and return?
It isn't possible to see in your pic what parts are accessable.
All clamps need to be accessable for inspection and testing.

 

[diychicken]

Yes, it's for flow and return, so x2. Had to add extra fittings to take the pipe lower down as previously it was right below the flooring so, to protect against nails and screws in the future I re-routed them.

Are you saying that every intermediate piece of copper between two plastic pushfit connectors needs to have an earth bonding attached? Even if it's only 2" long and is below the floor and not near any electrical cabling?

Is what you say for anywhere in the home or just higher risk areas like bathrooms?

And for the inspection part, that's fine for the pipe attached to the radiator tail as that's above the floor so the bonding can be accessible (although not necessarily pretty!).

Many thanks for your help

 

[Spark123]

The extraneous conductive parts which are accessable to anyone inside the bathroom need to be bonded. It doesn't matter about the ones below the floorboards. If you bond the flow and return then no need to bond the radiator itself.
Supplementary bonding is only carried out in places of increased risk such as bathrooms / shower rooms where the risk of fatal electric shock is increased owing to a lower body resistance due to lack of clothing and being wet.
There are certain circumstances where supplementary bonding can be omitted in the 17th edn regs.

 

[diychicken]

Cool. So it sounds like I only need to bond the bits above the floorboards - which are the pipes attached to the tails. That's a relief.

One final question, then. On the pipes to the old radiator, only the pipe attached to the tail on the return was bonded - not the incoming flow. That may have been compliant with regs previously. Does that still stand? I assume it's because the main flow, radiator and return tail are all part of the same conductor so only require 1 bonding. Is that right?

Just as an observation point - my wife gets mags like Real Homes, etc. and they show people's new bathrooms, etc. and none of the radiators ever seem to have bondings on them - how did they get around not having visible bondings?

Thanks so much for your help, Spark123

 

[Spark123]

If you bond one side then prove continuity by measurement (0.05 ohms or less) you can probably get away with not bothering with the other side.

If the pipework is all metal then bonding can be carried out close to the location i.e. in an adjacent cupboard. If the pipework is all plastic then the parts are not extraneous hence don't require bonding.
It becomes a bit of a nightmare when you mix the two together.

Also, as I said before there are certain circumstances that supplementary bonding can be omitted altogether now in the 17th edition of the IEE regs.

 

[ban-all-sheds]

I used plastic pushfit connectors with copper pipe.

Why?

 

[diychicken]

Because although I have tried soldering pipes, I'm not confident enough to do it on a live system. I also wanted to use something that I could put in place and, if the pipe was too short or too long, I could remove it and replace or cut down. Copper push fits can't be removed very easily. I used plastic ones that can be locked off and used plastic collets to ensure that they wouldn't come undone. The fittings are certified for central heating systems:http://www.johnguest.com/part_spec.asp?s=PEM03_S1

I know it's not the "ideal" or cheapest plumbing solution but it should be more than adequate.

 

[Taylortwocities]

Just as an observation point - my wife gets mags like Real Homes, etc. and they show people's new bathrooms, etc. and none of the radiators ever seem to have bondings on them - how did they get around not having visible bondings?

In the same way that the kitchens in those glossy mags dont have sockets and isolator switches. Just clean smooth surfaces that are unblemished by anything useful.

 

[diychicken]

Yeah, but the bathrooms in the mag are supposed to be actual bathrooms that someone is showing off - i.e. look what my £20k bought me