Need ideas for bathroom lighting and fan

Hi folks,

I have two bathrooms with nearly identical setups: one switch connected by 14/2 120v wiring to a vanity light and then on to an exhaust fan. When you toggle the switch, the light and fan both turn on/off together. The only difference between the two rooms is that I have back-of-wall access to the light and fan in one bathroom but not the other. I want to control the exhaust fan and lights independently.

Ideally, I would run 14/3 Romex and install a double gang box with two smart switches, but I’m not really sure I want to tackle that level of remodel right now. And anyway, I probably don’t have the skills or tools to do that for both bathrooms. What other options do I have?

I’m soliciting ideas for devices (Aeotec Micro Switch G2, maybe?) that will allow me to have independent control over lighting and fan, recognizing that I only have back-of-wall access to one of the bathrooms.



If you can find one, an innovelli fan switch would work for you..

if you have the Romex, you could (after disconnecting the power), fish wire from the fan to the vanity, then fish it to the box. this will give you a direct line to the fan. alternatively just fish another line from the vanity to the box, then disconnect the fan from the vanity and connect that to the new line run, again giving you a direct line to the fan. you can then use something like Leviton Decora 15 Amp Single Pole Dual Switch, White R62-05634-0WS ( to control each individually while maintaining a single gang box

I've got to do this soon. My plan is to put a Aeotec Nano switch either in or next to the fan isolator switch box (the fan side of the wiring), then leave the light turned on all the time but with a smart bulb in the light fitting

(Please note I am not a qualified electrician nor have I tried this out yet so no one should view this diagram as more than a suggestion!)

how would you control each fixture then? are you going to install separate buttons to control the light/fan? are you going to use contact/motion/moisture sensors? just putting the Aeotec Nano won't give you any control physically based on your diagram

Probably add a battery-powered humidity sensor, but more likely turn it on myself when I have used the bathroom and have a rule to turn it off after a certain time - but independently of the light, since I sometimes want to use the fan in the daytime when there is little point in having the light on, and other times I just want the light on minus the fan noise- for brief visits in the night.

You could just buy a fan with its own humidity sensor like this.

It would still be one switch but the fan would only come on when needed.

I think there would still be some rewiring needed to seperate that from the switched live. I am not sure what the OP is wanting to achieve it might not be humidity related

Depends on what he wants I guess. If all that’s needed is the fan to only turn on when the shower is running and not every time the light is on, then no wiring needed.

I have an innovelli red series fan controller on a bedroom fan and love it. Would it work for an exhaust fan though? I didn’t think they were compatible.

Yeah, I’m definitely aware that I can (in principle) fish some 14/3 (or two 14/2) romex and solve my problem the right way. But in practice, I’m not really up for that, especially not in a fully finished wall where I have to make a 90 degree turn.

Doesn’t zooz make a dual Z-wave switch?

A humidity sensor is an interesting idea I hadn’t considered. I’d prefer a solution where I can turn on the fan to cover “impolite” noises and vent embarrassing odors. :wink:

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Don't see why it wouldn't be. You might have to be creative with placement of the rf module.

Interesting. Jasco is very explicit about their fan controller not working with bathroom exhaust fans. I can also verify from personal experience that they don’t get along. Inovelli must be doing something differently.

Yes, but it requires a separate hot line to each device, so if your fan feeds power from the light fixture it would not work. Also FYI the zwave range on the ZEN30 is terrible. It needs other devices in the immediate vicinity to function. Zooz says it is due to antenna placement. Going to bust one of mine open one day and see if I can fix it.

I do like the idea of the nano switch. You could put it in the exhaust fan area or in the box with the fixture and connect it to the hot going to the fan. Heck you could even try out the Zooz ZEN52 which is a double relay (I think it would work for this). Then you do a smart switch that can do button events on the wall (Zooz switches and I am sure others as well). Disable physical control (or hot wire the light/fan wiring to always on). Setup button rules to turn the light and fan on/off, like single tap for the light and double tap for the fan or something. If you only do a nano switch on the fan side, you would need smart bulbs in the fixture as someone else mentioned.

He could wire the light and fan for permanent power bypassing the existing switch.
Use a Shelly type switch(s), or similar device, inside the ceiling box for both the light and fan. Control those with a wireless button like a Pico or EIRA.

Or as the OP asked, use this one from Aeotec. It will work with the light, but you may need something heavier for the fan.

Are bathroom fans not usually on the lighting circuit? Should be if it's triggered by the light switch, not meant to have power supplied by more than one

Mine had better be or my wiring plan will probably blow up my house lol(?)

My fan is separate from my light. Sure you can have a fan and light on the same circuit but most modern builds keep them separate.... (at least in my experience here in the US)

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There were few references to using "fan controller" type switches (e.g., the inovelli LZW36) in the thread above.

I'm 99.9% sure you should not do that. I researched a number of these switches when I was updating my ceiling fans and, from what I could find, all will be incompatible with a bathroom exhaust motor.

Here's a more detailed explanation of why. . .

My recommendation not to use a "fan controller" type switch for a bathroom exhaust fan has to do with how AC motor ceiling fans work. Those "slow moving" AC motor ceiling fans use a motor type know as a "split capacitor" motor which has a primary (running) and secondary (starting) motor winding whereby the speed of the fan is determined by varying the level of capacitance between the power source and these windings. There are some good videos on youtube explaining this. E.g., Capacitor Connection Diagram Of Ceiling Fan by Earthbondhon - YouTube

When you see a z-wave "Fan controller" switch, that generally means a switch designed to work with and control the speed of a split capacitor motor. I believe these switches do this by placing different capacitances in line between the power source and the ceiling fan motor.

As bathroom exhaust fan don't use split-capacitor motors, they are generally not compatible with "fan controller" switches. Note that the spec sheets for these switches will generally contain a warning about this. E.g., here's the Jasco spec sheet which warns that it is for split capacitor fans.

Note that you should also not use these Z-Wave Fan Controller switches if you have one of the newer "DC" motor ceiling fans as they are also not "split capacitor" motors.

What you can use, instead, is a basic "switch" containing a relay. The Relay on the Zooz Zen30 works well. But you should check that any switch you use is compatible with a motor -- not all of them are. The newer Zooz Zen71 switch also indicated it can handle a fan of up to 3 amps.



Sticking with your original suggestion to use an Aeotec, you could go with the Dual Nano in the light fixture box. One switched load to the light, the other to the fan. Your existing switch could get replaced with a button device, scene controller, or switch that supports "smart bulb" mode and double taps. One tap for lights, two for the fan.