Bathroom extractor fan. What am I missing?

[Capt Bravz]

I'm trying to replace the extractor fan unit in my bathroom ceiling.
The current one works fine, comes on with the lights and then runs on for about 5 mins afterwards when the lights are turned off. I'm replacing it because its just getting a bit noisy and I have purchased a 'quiet' version.

Units are a straight swap physically in the ceiling but the old one runs off two wires, one brown, one blue.
The new unit has points for 3 wires. N, L, and S/L

No combination of wiring has got the new unit to work whatsoever.
What is the elephant in the room please?

[Neil - YVM]

You may have 12V extractor, as these have a separate control box where the switched and permanent live + neutral connect, then a 2 wires going to the fan.

I'm not aware of separate controllers for 240V, but there may be. Try tracing the switched live feed from the light fitting to the extractor. (Usually a 3+E cable )

[oldnbold]

Are you sure that your old unit is not a 12V one. I made this simple school boy error a couple of months ago.

[Capt Bravz]

oldnbold said:

Are you sure that your old unit is not a 12V one. I made this simple school boy error a couple of months ago.

Ah...
Thank you. Yes. Old one is 12v, new one is 230v.
Now I know what the issue is how can/do I solve it or is it the case I need to buy a replacement 'quiet' 12v model?

[Capt Bravz]

Progress.
Been up into the loft, traced the wires back from the fan to a grey box labelled 'transformer timer unit' with a handy dial set to 5 mins.
Removing this will give me the 230v needed to make my new fan work or am I about to blow my roof off?

[oldnbold]

Capt Bravz said:

Progress.
Been up into the loft, traced the wires back from the fan to a grey box labelled 'transformer timer unit' with a handy dial set to 5 mins.
Removing this will give me the 230v needed to make my new fan work or am I about to blow my roof off?

I called an electrician in when I couldn't get mine to work and he told me 12V extractors were common in bathrooms, especially if near a water source. Mine could have been soaked by careless use of the shower, as it was in one of my BTL's I played safe and took the 240V one back and got a new 12V extractor.

15 mins later I had a new working extractor again.

[Capt Bravz]

Yep I think that's gonna be the way to go for me too. My fan is right above the bath/shower combi so best not to have 230v lurking around.
Many thanks for your help!

[Pheo]

You need a SELV bathroom fan - used where the fan is in a particular zone of the bathroom (see electrical regs) to reduce risk of electrocution.

http://www.plumbworld.co.uk/safety-extra-low-volta...