Combine light and fan swicthes


Old 03-17-07, 10:53 AM
Thread Starter
Join Date: Mar 2007
Posts: 2
Received 0 Votes on 0 Posts
Combine light and fan swicthes

Right now, the bathroom light and fan are oprerated from different switches. I want the fan to come on when the light switch is turned on, but I still want to be able to turn the fan on with the fan switch without turning on the light. Thanks in advance for any help on this.
Sponsored Links
Old 03-17-07, 11:16 AM
Join Date: Apr 2006
Location: New Bern, NC
Posts: 1,623
Received 0 Votes on 0 Posts
To do this you would need to use relays in the circuit. Electrically it is not very difficult, but you probably do not have room in the wall switch box, or the light fixture for the required equipment.
Old 03-17-07, 11:25 AM
Join Date: Sep 2000
Location: United States
Posts: 18,497
Received 0 Votes on 0 Posts
If you wire the light switch in series with, and downstream from, the fan switch, then you can approximate the behavior you desire. LS=light switch. FS=fan switch.

LS-off, FS-off => Fan off / Light off
LS-on, FS-off => Fan off / Light off
LS-off, FS-on => Fan on / Light off
LS-on, FS-on => Fan on / Light on

This means that the fan will always be on whenever the light is on, but you can also run the fan separately. To turn on both, flip both switches on. To turn on just the fan, turn the fan switch on but leave the light switch off. One downside is that if you turn on the light switch without also turning on the fan switch, nothing at all happens. This will confuse people who are unfamiliar with the setup.
Old 03-17-07, 11:40 AM
rdn2113's Avatar
Join Date: Oct 2002
Location: Wally World
Posts: 451
Received 0 Votes on 0 Posts
The easiest approach is to add a third switch that combines the fan and light together.

You can get a switch device that has two switches on one yoke so it will fit in the same space as one of the existing switches. The switches will operate horizontally (side to side) rather than up and down.

You could put the light on one of the horizontal switches, the fan on the other horizontal switch, and the light/fan combo on the remaining vertical switch.

If you want all the switches to operate vertically, you'll have to either remove the existing switch box and replace it with an oldwork three-gang box, or simply add a single-gang oldwork box next to your existing switch box.

One other option is to use a three-device switch, which has three switches in one switch device that that fits in the same space as one single-pole switch. You'll have to use a plate cover that covers the empty part of the existing switch box.

Be sure you diagram and label all the wires in your existing switch box before you pull everything apart. It will save you a lot of frustration!

Best wishes!
Old 03-17-07, 11:59 AM
Join Date: Apr 2006
Location: New Bern, NC
Posts: 1,623
Received 0 Votes on 0 Posts
I did not immediatly think of two pole switches. One two pole sw and on single pole switch would do the trick.

In the end, however it would still be just as inconvient to have to make sure the second switch is off, to turn everything off, as it is now to make sure the second switch is on, to have everything on.

Why is turning one additional wall switch on such an issue anyway? Finger getting tired?

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: