Earth bonding

[rishy]

Hi all

Need some help i need to add earth bonding to the gas and water / combi boiler.

I have the clamps and 10mm earth for the gas.

The question is what mm cable do i use the the water supply and can i link the earth bonding from the water to the combi boiler.

(so one cable from the electic direct to the water and then continues to the 5 pipes of the combi boiler)


Thanks
RiShY

 

[SeanT]

Why do you need to add bonding? Have you fitted the boiler yourself, or was it already there? If you haven't altered anything you shouldn't have, you shouldn't need to touch the bonding, despite the fact that it may not be correct, you're not expected to know and therefore shouldn't bother messing with it - it's probably worth making sure that your incoming water and gas are bonded, but the number of houses out there where it isn't is unreal - if you've fitted the boiler yourself, you need to do a LOT of reading.......

 

[jotto]

If you have a 10mm earthing conductor going to the water pipe, you can theoretically carry it on to the gas and also carry out cross bonding.

The main earthing conductor should be 1 continuous piece of cable, ie not cut. It should run from your main earthing terminal on to the water and then continue on to the gas. Bear in mind that the gas should be bonded as near as practicable to the point of entry to the house, generally it should be within about 300mm of the gas meter.

The cross bonding can be carried out by simply fitting a clamp to each of the pipes at the boiler and using 6mm cable...I like to use 10mm just to be on the safe side.

10mm to the water stop tap, 10mm to the gas near the meter and what ever floats your boat for the cross bonding, use the 10mm if you have enough.

 

[SeanT]

Bear in mind that the gas should be bonded as near as practicable to the point of entry to the house, generally it should be within about 300mm of the gas meter.

Specifically it has to be within 300mm of the gas meter unless there is a very good reason not to or the gas meter is outside....

 

[jotto]

Bear in mind that the gas should be bonded as near as practicable to the point of entry to the house, generally it should be within about 300mm of the gas meter.

Specifically it has to be within 300mm of the gas meter unless there is a very good reason not to or the gas meter is outside....

WHS^

 

[SeanT]

Know slightly more about gas than leccy, still strictly diy though (but a degree in physics helps me pick up most of this stuff from a techincal point of view - shame I seem to need a degree in law to do any DIY.....)

 

[rishy]

Thanks for the fast replys

This is a house i have just moved in to -

At the moment there is no earth on the gas, water or the boiler.

The idea i have is to run 1 x 10mm wire from the gas to the earth.

Then run a second wire from the 5 pipes of the boiler to the water supply (which is less then a meter away) then to the earth on the electric

idea 2 :
run a third wire from the combi to the earth

last idea is :
and last idea run a earth from the electic isolater of the boiler to the pipes

 

[rishy]

bonding for the gas and water will be within 30cm of entry point

 

[SeanT]

As above, if it's all that close together then just join everything together with 10mm in a sensible order. Nice to do the water and gas seperately, mostly so that nobody messing with one needs to mess with the other if they aren't sure and are faced with something more complicated / confusing.

 

[Lectrician]

'Cross Bonding' IS NOT required between the boiler pipes.

This has been removed from the corgi guides now so as not to contractict our regulations (which do not require it).

If you really wanted to 'cross bond' them, you would use 4mm, and there would be no requirement to 'earth' the bonding.

The main bonding should be within 600mm of water stop tap and gas meter, on consumers side, before any tees. 10mm for a standard domestic. If you loop from water to gas or visa-versa, do not cut the conductor at the intermediate point - just strip the insulation and place below clamp.

Hope thats clear