Supplementary bonding in bathroom, proximity to radiator

[-Sean-]

Hello folks.

I'm replacing the cable to my shower with 10mm² following fitting a new consumer unit as part of general updating works.

Notified BCO early in year, hence working to 16th.

Existing bonding was in place from shower to bath taps, but not to sink or radiator as far as I can see. Sink is easy as it's next to bath.

Radiator is on the other side of the room. I can easily bond the radiator pipes under the floorboards on the landing, about 1.5m - 2m from the radiator itself, but is this acceptable? Can't see in the reg's any distance quoted other than 'close proximity'. If I bond the pipes does a cable need to be run to the radiator itself or can the continuity through the compression fittings be relied on?

Any advice welcomed. If I have to take up the flooring so be it...

 

[tSpark]

New consumer unit and change of a final circuit cable is a partial rewire
Persumably all your Main bonding has been upgraded to suit so why not just work to the 17th and omit supplementary bonding (providing all the appropriate conditions are met ie. disconnection times, rcd protection etc)?

compression fittings can not always be relied on for continuity (in the eyes of some governing bodies)

Is earth clamps underfloorboards classed as readily accessible? no

 

[sparkyspike]

Sounds like you've already fitted your CU to 16th ed., so yes, bond your radiator - if it's connected to copper - but make sure the bonding point is accessible. You need to get as close as you can to the radiator. Can you not fish a cable through somehow? Or go into the wall?

 

[-Sean-]

I wondered about doing it to 17th, but I'd then have to put cooker outlet on 30mA RCD (it has a socket) and I think I have to fit a second 30mA RCD and separate upstairs and downstairs lighting circuits (correct me if I'm wrong). Unfortunately running a second lighting circuit in for the upstairs lights would be a lot of work. I've already forked out for a 100mA time delay RCD so it'd be a bit of a waste of money to take it out and put another 30mA in.

Good point about bonding being accessible, I think I'd better have a go at fishing a cable in under the floor to pop up by the pipe.

It all seems a bit over the top, shower is on 30mA RCD, lights (and whole installation) is on a 100mA S type. Continuity from shower CPC terminal to radiator pipe measures less than 0.02 Ohm (KMP3050) currently. (Maybe I'll find it's bonded under the floor)

 

[tSpark]

Yes mate, youd have to protect all circuits, with a 30ma RCD, (unless your light switch drops etc are protected in earthed metal conduit, Doubtful)

Since you notified BCO before 17th came in, should'nt be a problem to finish in 16th if they're happy with that. Good luck with the supp bonding