Bathroom fan wiring query (sorry!)

message from Lobster on 12 May 2004

I know that bathroom fans seem to be one of the most oft-covered
I'm installing a simple bathroom extractor fan (Screwfix 15927); I'd
like to wire it through a 2-gang light switch on the landing; ie, the
two switches would control the bathroom light and fan completely
independently. There's no timer, humidistat, or anything else; just
straightforward on-off.

Is this permitted under the regs? I can't see why not, but the fan
instructions state that I can only wire it independently using a
pull-cord switch, or wire it in parallel with the bathroom light.

And does the fan still need to be wired through a double-pole
isolation switch, despite not being wired to the light? Can I just use
a double-pole FCU like Screwfix 16437?

Thanks
David

Wheelbarrowbob replied to Lobster on 12 May 2004

thats how you do it then>

fans are usually wired into the lighting circuit using 3 core cable and
isolated using a fan isolator switch

BigWallop replied to Lobster on 12 May 2004

It's best to install a localised double pole isolator switch to a fan circuit for
servicing purposes, and it isn't necessary to have a pull cord switch if the switching
is being done from outside the bathroom where you don't have your hands in a wash
basin full of water. So, yes, you can install a two gang switch outside the loo room
to control the fan and lighting independently of each other, but it's best to have the
live and neutral for the fan running through a double pole switch (5 amp rating should
be enough) and install it either above or below the two gang switch before the supply
carries on to the fan itself.

Lurch replied to Lobster on 12 May 2004

I think it just assumes you are putting the switch in the bathroom,
all of my fans are switched from a seperate wall switch outside, and
it's to the regs.

Yes, you still need an isolator, no need for an FCU though, just a
double pole isolator like an immersion heater switch will be fine. I
usually use a TP fan isolator though, so it's got a label saying what
it does.

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