bathroom extractor fan

[ccrobins]

My house has recently been re wired but as part of that an extractor fan was put in that didn't have a timer - it just came on and off with the lights. I decided to replace the extractor with a timer one that also had a humidistat. before removing the old one i noted which wires were neutral perm live and switched live and wired up the new one accordingly. The new one only works with the lights again and so i wonder whether the perm and switched live have been wired correctly during the rewire or maybe they have just been mixed up so perm is switched and vice versa - can i switch these around to test just in case without causing issue ?

an isolator switch is also in the bathroom but i haven't touched that

- any ideas ? as you can tell i am a novice with electrics !

 

[electronicsuk]

Swapping what you believe are the permanent and switched live feeds will do no harm if they are both indeed live feeds of some sort. Obviously if you have them the wrong way round then a timer fan will behave as you have described.

You could invest in a cheap multimeter and test to see which is which if you'd prefer.