On 03/05/2021 13:37, Scott wrote:
On Mon, 3 May 2021 13:14:37 +0100, Robin wrote:

On 03/05/2021 12:45, Scott wrote:
On Mon, 3 May 2021 01:38:21 -0700 (PDT), Jedzi
wrote:

I've got an ancient, maybe 40 or 50 years old, switch for the immersion heater in my airing cupboard. It's a thin-ish one, mounted on the wooden door frame.

Increasingly, it gets hot in use and has started to smell slightly (I think it's a heated plastic type smell).

I want to replace it with a switch like this https://bit.ly/336ClVA , mounted in a steel back box, on the wall next to it. Am I allowed to do that?

I would say no. 240V x 20A = 4,800W. I believe some immersion
heaters can draw up to 6kW. Even if yours doesn't, someone might
upgrade or replace it.

If someone upgrades it then it's their responsibility to check the
switch and upgrade it if necessary. Ditto the cable and MCB/fuse.

True, though I tend to follow the Brunel approach.

I would still suggest OP needs to check the power rating of the heater
unit before deciding whether a 20 amp switch is suitable.


If it's a standard 3kw immersion element then simply checking the
tightness of the connections inside the existing switch may be all
that is needed.