In article ,
BodgeIt wrote:
First, are you sure it's a 30 amp MCB? Immersions are usually 3 kW, so
16 amp would be usual. You need to identify the cable feeding it as 30
amps is too large for the normal 2.5mm TW&E.

However, you don't need to use an FCU when converting an immersion
heater circuit to a radial. Change the MCB to a 20 amp one. You can
then have as many sockets on that radial as you wish, as the MCB will
prevent overload of the cable.

You're correct, it is a 15A MCB, I confused it with the cooker MCB. I
thought fitting an FCU would be better so that if the central heating
ever fails and we need emergency hot water I can isolate the additional
socket and temporarily reconnect the immersion heater.

Not quite sure how an FCU would make that easier.

If you really want that, fit a socket in the airing cupboard so the
immersion can be plugged into that. Wire the new bedroom socket in 1mm
flex fed from a plug too. Then all you need to do is swop the plugs.

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*Why do we say something is out of whack? What is a whack?

Dave Plowman London SW
To e-mail, change noise into sound.