Switch to appliance cable length

Yemmy500 · Feb 5, 2016

Good morning all.

I've just moved into a property with no central heating in the rear extension. There's a small WC at the back which has 2 fused switches, one for a saniflow and one for a towel rail on the right hand side of the doorway. The towel rail switch is currently hardwired to a 1000W oil rad, which I'm going to remove. The whole of the left hand side of the extension has no power sockets, they are all on the right. I have just bought a 2kw electric wall heater which I want to mount on the left wall just outside the entrance to the WC. I want to use the fused switch to power it instead of the little oil rad.

Are there any limitations to the max length of wire between the switch and the heater? In terms of distance across the floor the two are only about 1.5 metres apart, but the wire would have to be run over the door of the WC and down inside the wall to the wall heater. Any advice very welcome. Thanks for your time everyone.

Chris

apprentice87 · Feb 5, 2016

Good question! Assuming you use sensible sized cable [what you thinking of using] then, within reason, no.. If the cable was going to be 30 yards long you might have to think about it, but for what you describe it should be fine!! When you say fused switches, i take it you mean FCU's?? [like a light switch looking thing with a 13A fuse holder in it]

john..

Yemmy500 · Feb 5, 2016

Hi John, thanks for the quick response.

FCU is exactly what I meant, and (from my basic maths) for a 2kw heater a 13A is still a suitable fuse?

In terms of what cable to use, that would be my next question. Going up and over the door looks like about 7m.

Cheers! Chris

apprentice87 · Feb 5, 2016

Well, if it was me i would install a new socket on the wall where you want the heater, fed from the FCU. Put a 13A fuse in the FCU and then run a new cable to the socket. I would use 2.5 twin and earth, [this is almost certainly what is feeding the FCU..]

Do you know where the FCU is fed from?? Spurs off spurs are not allowed.... Another thing is, has your CU got RCD's installed?? If you install a new socket, or cable inside a wall [do you know about safe zones] less than 50mm from the surface of the wall, it will have to have RCD protection..

john..

Doc Hudson · Feb 5, 2016

If this is going up and over a door and down the other side, unless it is surface wired I would have thought it will almost certainly fail to comply with safe zones guidance.

Doc H.

Yemmy500 · Feb 5, 2016

Thank you both.

Apprentice - I'm afraid I don't know where the FCU is fed from but yes the CU has fixed RCDs. I wasn't aware of safe zones but only through lack of experience not because of a blatant disregard! It's definitely something I will research further if I decide to dig in above the door.

Both - If I were to surface wire then would this be the safer alternative?

Cheers, Chris