Installation of bathroom extractor

[balugaa]

Ok have been totally baffled by this, given its one of those super simple projects but feel i must be missing something.

The mrs been complaining about the amount of noise the bathroom extractor fan makes, so i said maybe its time to get it replaced.

Its one of those numbers that turns on with the lightswitch

So went off to the local store bought myself a new bathroom extractor fan, came home removed the old one, wired up the new one, turned the mains back on, turned the bathroom light on and nothing ..

Dodgy extractor i thought, so took it down, and rewired the old one, the old one turns on and everythings back to normal again

Go back to the store, get it replaced, wire it up, and same problem doesnt go on with the light,

I have checked and rechecked all the instructions, dont think there is a hidden switch somewhere, wires seem fine, given when i connect the old one it works fine.

So 2 new ones not working seem to suggest i might be doing something wrong ..

Any ideas as to what i could be missing ?

 

[xr4x4]

What's wires were on the old unit and what on the new?

Was the old unit timed? And the new?

 

[balugaa]

What's wires were on the old unit and what on the new?

Was the old unit timed? And the new?

No timer, its just a bog standard unit

in terms of cables, from the main cable a red and a black these are extended as in red to brown , black to blue which then feed into the old unit into Live and Neutral,

The new unit has live and neutral also .. (the current new one is a manrose basic gold