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ecobee3 wiring to Aprilaire 560 (older) humidifier

rathrboutsiderathrboutside Member
edited January 4 in ecobee

I need some help figuring out how to wire my humidifier to my ecobee3. I've tried ecobee support a few times with no luck. My setup is as follows:

  • ecobee3 (new late 2016) firmware
  • 1 stage furnace
  • gas heat
  • air conditioner
  • Aprilaire Humidifier 560 (older)



My humidifier used to be hooked up to a manual humidistat dial. One wire of the Solenoid was hooked up to the humidistat and from the humidistat to a Goodman pressure switch in my furnace. The other wire from the solenoid was hooked up to a bolt in the furnace (like a grounding bolt). My humidifier worked this way. I would set the dial to a humidity level and the humidifier would kick on when the heat ran.

I now have my humidifier hooked up as follows (told to me by ecobee support). My ecobee3 ACC+ terminal is wired directly to one side of my humidifier's solenoid. The other wire from my solenoid is hooked straight to my furnace's C terminal. My humidifier is not turning on, even though the ecobee3 says the humidifier is running. I told my ecobee3 the humidifier is an evaporative, 1 wire setup. I set the ecobee setting humidifier to "on" and set the humidity level to 50%, just to try it out. Nothing is happening, the solenoid isn't sending any water.

Does anyone know what I'm doing wrong? Did I blow the solenoid after having it hooked up differently for a bit? Thanks in advance!


Dry Hands


  • kevinmcckevinmcc Macomb, ILMember

    Double check the wiring, that should work. Check you have 24vac between between the solenoid wires when humidity is being called. If don't you don't try jumping R to ACC+ and see if the solenoid opens. If does the Ecobee maybe bad. Email support.

    If you can measure 24vac between the solenoid wires and the solenoid is not activating, then the solenoid is bad.

  • kevinmcc, Update: I spoke with ecobee support a few more times and they confirmed my wiring was correct. I also (dry connected) jumped my R and ACC+ together and confirmed the solenoid and humidifier turned on and worked. I then put the ecobee3 back on the wall and tried the humidifier setting and nothing worked, even though the ecobee3 said it was working. This was with the ecobee wiring saying it was a 1 wire humidifier setup, which it should be. Support then had me use the testing mode on the ecobee3 and that fired up the humidifier, good! I then ran the ecobee normally and the humidifier worked. Weird! Great! However, I now noticed the ecobee3 says I have the ACC+ and ACC- connected. weird again... I never changed that. I'm not going to reconfigure the humidifier to 1 wire, because that seems to make the problem come back and the only way for my ecobee to run the humidifier correctly is after I go into testing mode.

    I'm now starting to think this is an ecobee3 software bug or a problem with my unit.

  • kevinmcckevinmcc Macomb, ILMember

    Sounds like a firmware bug, several people have said they have same sort of issue you have. Hope they fix it soon.

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