Thanks for the advice guys tried what you suggested and now have a fully functional fan which switches on and off with the light.
Really pleased, can sleep well tonight!
I just bought a basic Extractor fan for my bathroom.
It has not timer or therma.
My flat still has old wiring but when I removed the old broken fan the there are 3 wires. Brown, Blue and Yello/Green.
The fan only has two connection sockets which are marked Live and Neutral.
I wired...