Bathroom fan

I’d like to use a Z-Wave switch (Evolve LSM-15) to control a bathroom fan. I see there are numerous ways to have a switch turn on and off based on a triggered sensor/schedule/etc. for a specified period of time.

However, is it possible to have a switch that has been physically turned on automatically turn off after a specified amount of time? Essentially making the switch operate like a timer switch when manually switched on?

Hi Sean,

I understand what you’re saying. I have program i modified in Smartthings that may serve as a work around. Here’s my scenario:

My Master Bathroom door is open. If some goes into the bathroom nothing happens. I do not have any motion sensors in place however if you were to close the door the light would turn on and if you did not open the door in a defined amount of time the exhaust fan would turn on as well. Once you open the door the exhaust fan would turn off and the bathroom light would remain on for an additional 5 seconds given you enough time to find your way if you got up during the night.

I did that for all the lights and the fan for my daughter’s bathroom since she’s really great at turning them on…but never off. I went to Tiger Direct (store is local in my area) and bought a motion sensor for the bathroom, and after a certain amount of time of no motion it will trigger everything off.

Here’s what I bought:

Motion Sensor

In your case it sounds like you’re looking for a Smart App to do something similar. I haven’t thought about something like that, but I’ll poke around in some of the existing apps to see if anything can be easily put together.

I too have the same issue with bathroom lights/fans.
What I’ve done for my bath/fan combos isn’t controlled via zwave (which I didn’t care about in this situation), however it does meet the manual on/auto off requirements.
Additionally I’m using the Legrand Adorned product line for outlets and switch devices.
Anyway, I did the following:
Legrand SensaSwitch manual on/auto off (with adjustable timed off) motion sensor
This is connected to the lights.
The NO side of this device is also connected to a Legrand paddle (with the push button hack), the NO side of this paddle controls a 120v SSR configured as a latch. The SSR output is fed to the fan, the SSR input side is also fed from the SensaSwitch NO side.

The net effect being, turn lights on, (optionally hit PB for fan), after no motion for the configured delay time, the Sensa turns off the light, also turning off the fan if it was on.

The drawback to this configuration being no fan unless the light is on, the advantage is only one control/motion device to purchase/install and configure.

The “Power Allowance” app does precisely this.

Setup-More-GreenLiving-Power Allowance


Thanks @scottinpollock, worked like a charm :slight_smile:

For those looking for this now that 2.0 app has been released, you likely need to go to the developer tools online and create a new SmartApp selecting “Power Allowance” template. Save and publish then go to the phone app and configure the power allowance smartapp in the “My Apps” section. I was unable to find this otherwise… hope it helps!

It’s still there in Lights & Switches, just as before. It’s called “Turn off after a period of time”.

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Ah, found it - thanks!

I really don’t use that dashboard at all so no wonder I missed it. Given the number of devices in my system (>60), that screen would get crowded so I don’t see much use for it however I guess I can just add the lights that need to be controlled with one of the option made available within… and then just ignore it. However, the “Power Allowance” smartapp I found in the templates seems to do what I need without requiring me to use that dashboard so I went with that.

I don’t use Lights & Switches for anything but a repository for things that use the embedded apps found there. The UI aspect of it is pointless and I don’t use that. For the apps that are in there, it’s better to use them than to use a custom app because of the way Support treats it if you have a problem.

I do this with a few GE zwave switches in the house. Kids bedroom lights shut off after an hour. Bathrooms 15 minutes.

Yup, this is what I use. Wish there the new smart lighting had this feature.

Hello Mike, I installed the Legrand SensaSwitch manual-on/timed-off in our laundry room to operate the Ventilation Fan. Unfortunately, it does not work. I hooked up the Hot wire, the 1-Pole, and ground wire. The instructions also mention a White wire, however, I am not sure if I have such a wire available. It was not connected on the old switch. However, there were 3 white wires all stringed together and connected with a wire connector, which I found inside of the outlet box. Any ideas?

Thank you.

yup, the white wires are the neutrals, add another white one and run it to the switch, it should work then.

Yeah, I took one of the 3 whites (leaving two of them still together) and ran it to the switch but no luck.

ummm, you can’t do that…, put that one back, and bring a new one to the switch.
you can’t just randomly disconnect wires without knowing exactly what you’re doing…

okay, I think, for that I need an electrician…?

I guess, if you don’t have any romex kicking around…
you have three white wires connected together, you just need to add a 4th one in that bundle, the other end of that fourth wire goes to the switch neutral connection that you’re missing.

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As @Mike_Maxwell pointed out, The neutrals always(I’m not an electrician but as far as I know this is true) stay together, so you need to add a wire to the bundle to go to the switch.

I made this same mistake on my first installed switch.