On Thursday, 22 August 2019 19:16:05 UTC+1, Chris Green wrote:
We're aiming to put an electrically heated (as well as CH heated)
towel rail in the new shower/wet room. How are these normally switched
on and off?

A relative of mine has an electric towel radiator. It takes hours to heat up, so he leaves it on 24/7. Otherwise he'd have to plan in advance, which isn't going to happen...