DIY Doctor UK DIY Forums

Hi all. I've read all of Google trying to figure out why my new fans aren't working so I've come here for advice.
I'm replacing an old bathroom extractor fan with a new one but can't get the new one to work at all. I've even tried two new fans and can't get either to work.
There are three wires coming from the ceiling - brown, black and grey. None of these are permanent live.
The first extractor I've tried is a timer model and has space for three wires but no configuration works. (This includes using a loop from L to LS.)
So I got a second extractor - one without a timer and with only two spaces for wires. But again, no wire configuration seems to work.
I'm not an electrician but I have been meticulous in being safe and ensuring everything is connected correctly each time.
But the whole thing has me baffled. Am I missing something obvious? Why won't either new fan work when the old one does?
Any help greatly appreciated.
Thanks in advance.

Since it is down to who ever initially installed it what colour does what, it is not possible to advise remotely.
I would however suggest you put the old fan back and see does that work, as you may have either broken a wire, or pulled one out from a connection you can not easily see.
Also when you are working on anything electrical you should always have a means of safely testing, which you havent.
If you still get nowhere, you are going to have to get someone in.

Sorry, I should have said - I have reinstalled the old fan and that does still work.
Is there some quirk of new fans that could mean they don't work but the old one does? I mean, perhaps these days a permanent live might be required - or something like that, that wouldn't necessarily effect my old fan but does effect any new fan installations on my current wire set up?

Have you tried putting a flex and a plug on the new fan to establish does it then work?

If the old fan works when re-installed, and the new one doesn't work, it is either the new fan or something you are / are not doing. As I first said, unless you have a safe way of testing (Which you should have BEFORE you work on anything electrical) you are going to have to get a competent person in.