Thermostat trigger

I have an auxiliary fan that enhances my HVAC airflow. I only want it to be on when the Ecobee3 starts a programmed cycle. I have seen many custom thermostat apps here, but don’t seem to be able to find this. So essentially, when Ecobee3 turns fan on, then zwave event turns fan switch on.

Any help will be much appreciated. I don’t want to have to go to old school and use a 24 volt ac relay on the air handle to trigger this event.


This is what I’be been looking for! I also am looking for a smart app that I can use to turn on a few fans in ducts and in rooms but only when the ecobee thermostat calls for heat/cool/fan, have you had any luck? Does anyone know of anything like this? I started trying to make a smartapp but am woefully unprepared.

Any help from the SmartThings world??

I tried to find an elegant solution for this as I have an auxiliary fan in another section of the house. The basis for the wave trigger was the MIMOlite.

I ended up getting a 24 volt relay, a low voltage transformer from some electronic device I didn’t have anymore and the Mimolite. I tapped off of the fan in the furnace at 24 volts, which opened up the relay to trigger the Mimolite at a lower voltage.

This has worked for years flawlessly. I mounted all of this in a metal box on the side of the furnace.

Noted, thank you.

Unfortunately I don’t see that working for me. I’m trying to turn on 4 fans I have sitting in front of the vents in various rooms of my house (Den, master bedroom, great room & kitchen) and all of those plugs and fans are a considerable distance from the furnace.

I’m kind of surprised no one has come up with something comparable here.

Oh well, thank you!

The MIMOlite puts out a zwave signal when triggered, so you don’t have to be next to the other components.