chris French wrote:
In message , Geoff Norfolk
writes

I have a fairly powerful extractor fan fitted in my bathroom ceiling
however
it has no overrun timer facility so that when I switch the light off, the
fan immediately goes off. Anyone any ideas/recommendations for how I
can add
a suitable timer to it..... really need it to run for an extra 20
minutes or
so.

I used a humidistat to control mine.

Actually I'm just about to swap an overrun timer model to one which has
both overrun (needed cos it's an internal bathroom) as well as a
humidistat, in an effort to try and control a general condensation problem.

I was wondering, what % humidity should I set the thing to? I'm sure it
will want a bit of calibrating anyway, but a starting point would be
useful. Also, it's for a property which I rent out, so I won't have too
much opportunity to fine-tune it.

David