Post
by ericmark »
Fri Sep 29, 2017 11:04 am
Depends how wired, many fans use a double pole switch rather than intermediate or two way switch to comply with regulations.
If you have a non opening window you must be able to switch on the fan without the light, in fact there is no requirement to have the fan connected to the light, one method is to use a double pole light switch so one pole works lights the other pole works the fan, so fan and light are not electrical connected it is just a physical connection of the same rocker working both, a second auto return switch is then the second switch allowing it to trigger fan without switching on the lights. Common to use grid switches so you can mix and match switch types.
However it seems local authority building inspectors often turn a blind eye to having to switch on lights to work fan, so you also find a lot of illegal units, in some cases they were not illegal when fitted, but when a single glassed window was replaced with a double glassed unit the opening bit was missed out to reduce cost. And with an opening window you don't need a fan so it could be wired any way you want.
