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?
Unless it has it's own seperate circuit back to the CU I would use a
switched fused connection unit ( similar to your proposed one but with
a fuse). Search on Screwfix for switched fused spur.