Replaceing Bathroom extractor

[g4jnw]

I want to replace my bathroom extractor - looks quite old and is a
strange size (I think) the front cover is, 160mm x 160mm. I can't see a
make on it but it is one of the type that switches on and off with the
light and stays on a minute or so after switching it off.
I want to replace it as its noisy but with a pull switch type so it
doesn't come on with the light all the time.

Any ideas on replacement? I don't need to replace the outside wall
louvre as it looks and works ok.

it says 5927 timer model on it.

Notice that it has 3 wires - 2 red and one black, if I was replacing it
with a switched type how many wires do they have - thought they had 2
wires? would it set any problems ?

L , N , SL are marked on the present extractor

 

[whistler]

Because it has a timer, it needs a permanent live connection (L) so that it will run after being switched off by the switched live (SL). Bear in mind that (L) will always be live even if the fan is switched off.

 

[JohnD]

If you take the old fan off you will very likely find it has a plastic duct of 100mm diameter built into the wall (a piece of soil pipe can be used). This is a standard size and almost all common bathroom fans have a spigot that fits into it (some big ones are 150mm).

A new fan will be quieter, you may find that it doesn't irritate you and you don't mind it coming on with the light. Fans like that are much better at keeping bathrooms dry and non-smelly as people tend not to bother manually turning fans on.

If you spend the extra on a Centrifugal fan (which will have a bigger enclosure) it will be quieter and more powerful than an ordinary Axial fan.