Does bathroom radial circuit need updating?

5 May 2015
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United Kingdom
Hi all,

Currently undertaking some bathroom electrics.

In place was a 16A radial circuit feeding a towel rail and fan heater in my bathroom.

I want to remove the fan heater replace the towel rail and then add underfloor heating to it.

The flat was built in 2001. Am I right that new standards require that circuit to be an RCD ring now if i make any alterations to it?

Many thanks!

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The circuit will need RCD protection.

I guess by
16A radial circuit
this is a single cable coming direct from the consumer unit, with a 16A MCB protecting it?
If so, you could replace the MCB with a 16A RCBO to provide the RCD protection.

You will need FCUs (with the correct fuses) near the bathroom to provide the necessary protection and switching for the towel rail and the UFH.
Thanks TTC,

I don't know a great deal on RCD protection and thought i'd have to create a ring out of it so highly appreciate the pointer to the 16A RCBO!
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Bit of an old blurry image i have from my phone as im not at the flat right now.

The circuit in question is three left from the main switch labelled 'focal point heating'

Correct me if i'm wrong but from a google image search hager rcbos have an indicator on the bottom and a blue test button top right (the blue you see in this image top right is just part of the printed design, no test button)
Only the socket circuits (on the left) are RCD protected.

You could move the 'focal point heating' MCB over to the left hand side to include it with the other RCD-protected circuits, but that will involve re-jigging the consumer unit. More a job for an experienced sparky I would say.

Or install an RCBO, as I suggested.

Also re
thought i'd have to create a ring out of it
what is this insistence on amaking the circuit a ring final?
You have a 16AMP radial circuit which is more than adequate for the loads you have in mind.
New electrical work in bathroom, requires building control notification.
Any electrical work you do (or anybody) in a domestic property, should comply to part p of the building regulations.

If you don't know the difference between a ring, radial and RCD requirements, or a knowledge of what they do and don't have an understanding of inspection and test procedures, and their findings and the test results taken (which must be taken and documented), then time to call someone who does, no disrespect or anything!
Fair comment about the rcd knowledge. Not to worry it's getting certified properly by a sparky. I've had 10+ electricians turn the full job down or accept it and not turn up hence the diy undertaking.
That is regrettable, but safety is paramount, not only for you but also anyone else how may come in contact with this work.
Completely agree, thanks for the concern. Rest assured all parts of my notifiable work will be certified to meet Part P before any use is made out of it even by myself.

I fully encourage anyone to exhaust their efforts on getting a registered electrician in to do this level of work.
You understand you need to register the work with the LABC or third party tester BEFORE USE START not after complicated.

There are third party testers but I have noted most seem to be firms involved with plumbing and kitchen fitting which makes me think this is a method used for plumbers, and kitchen fitters to do work and then get the firms electrician to sign it off. As to if willing to really sign third party I don't know and where I live it's still not permitted so would be interesting so see if it's really happening in England.

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