Okay that’s great thanks, I just thought I was dealing with a perm live to the stat and a switched live from it to the fan. Didn’t realise they came with a lot more options
So I have a normal light switch & fan installation whereby you turn the light on and it also turns the inline extract fan in the loft on for a few minutes on the timer after the light switch has been switched off.
What I want to install is a humidistat that also turns on the fan when humidity...