Earthing radiators and towel radiators.

[judder]

Hello. I've just replaced a standard radiator in my bathroom with a (non electric) centrally heated, metal towel radiator; you know, one of those ladder type things. My central heating system is fed by plastic pipes.

Elsewhere on this forum I have read that if radiators are fed by plastic pipes they do not require earthing. However, all of my standard radiators are earthed, despite the pipework being plastic. In my bathroom I now have an earthing wire (which was clipped on to the radiator I've removed) and nowhere obvious on the new towel radiator to connect it.

Given that there is no electrical heating element in the towel radiator and that my pipework is plastic, is it ok just to ignore this earthing wire and hide it under the floor boards?

If it is ok to ignore earthing my new towel radiator, why are all my other radiators earthed?

In any case, why is the earthing required? I assume that it is for removing unwanted charge build up, but why would there be a build up of charge?

Thanks very much in advance.

 

[judder]

Sorry for mis-posting and thanks for the link, which I had read. Please correct me if I'm wrong, but it confirms that where plastic pipework is present, radiators do not require earthing, so I needn't worry about earthing the new towel radiator.

If that is the case, why did the people who built my house go to the trouble of earthing all the radiators? I'm questioning their wisdom not the forum's!

 

[Taylortwocities]

Its very likely that the electrician did not talk to the plumber (yes i know, it can happen, sometimes).
Better there the bonding is there, than not at all.

By the way, its bonding, not earthing. The link above will explain the difference - if you can be @rsed....

By the way (2). In new build houses, under the new wiring regulations, bonding may not be necessary in bathrooms. But other, much more stringent, safety devices now have to be installed.

 

[sparkyspike]

As you suspect, you do not need to earth-bond metal radiators fed with plastic pipes. Often an electrician (using the old 16th edition reqs) would fit supplementary bonding to a bathroom before the plumber had done his job, anticipating copper pipes. Plastic pipes do not introduce an earth potential, nor does the water inside them. Essentially the radiator electrically is floating in space. It does no harm to bond it in this case.

 

[judder]

Thank you very much for your replies. That clears up the matter and sets me at ease. Bonding, not earthing; I'll take that on board, but I'm not sure I understand the difference.

The electrical supply in the house is earthed, i.e. connected to the (relatively) fixed potential of 'the Earth'.

The bonding process connects all the bonded components together, making them of equal potential: are they then connected to a 'fixed earth-like' potential or just left, 'suspended' at their own equal (but different from 'earth') potential?

 

[Taylortwocities]

You win the smart prize of the morning!
They are all connected together to make them the same potential. If they are all the same potential then you dont get a shock if there is a fault and for some reason the radiator is a different voltage to the bath tub.

All these items are bonded together. Other items bonded will be the lights, shaver points, etc etc. These may be connected to the main earth through their own circuit wiring but we dont bring an earth wire all the way from the fuseboard to connect in the bathroom.

 

[judder]

Thanks very much. Very helpful.