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Wire the 24V solenoid on your humidifier to an Ecobee

SteveSteve Seattle, WAAdministrator

Someone asked how to do this today, so this is basically a summary of my step-by-step instructions (with pictures!) of my instructions how to do this on my blog:

http://stevejenkins.com/blog/2013/12/how-to-wire-a-humidifier-to-an-ecobee-smart-thermostat/

Again, this assumes you have a humidifier that is always powered (like with a 110V wall plug) and merely actuates the solenoid to activate the humidifier when it's called for by the Ecobee.

1) Use a short piece of wire to connect RH to ACC1r on the Ecobee EI.

2) Use a long piece of wire to connect ACC1 on the EI to either of the solenoid leads on your humidifier (I promise - it doesn't matter which one).

3) Connect the COM terminal on your furnace to the other solenoid lead on your humidifier.

4) (optional) On your Ecobee, go to Installation Settings, and turn the "Humidify only while Heating" to "No" if you want that option.

And that's it! It should take you 5 minutes to wire it all up. Again, hit my blog link above for close-up pictures of the wiring.

Comments

  • pvr4mepvr4me Member

    Hi Steve, it was me that asked that question.

    A small follow-up. The wiring diagrams in the Installation Manual always seem to show the humidifier connected to ACC3 (with an HRV on ACC1 and a de-humidifier on ACC2). You used ACC1. I take it that "1" through "3" are interchangeable and we can use the first available one?

    Craig

  • AndrewGAndrewG TorontoEcobee Employee

    You are correct in your assumption. The diagrams in the manual are meant to be examples when using ACC relays. You can use any available relay for Humidifier/Dehumidifier or HRV. Just make sure your wiring corresponds with the thermostat configuration.

  • Does the Ecobee turn on the furnace fan automatically whenever there is a request for humidity?

  • SteveSteve Seattle, WAAdministrator
    edited September 2014

    Barker492 said:
    Does the Ecobee turn on the furnace fan automatically whenever there is a request for humidity?

    Yes. The humidifier will run under these two conditions:

    1) If system is calling for heat/cool AND humidity, the humidifier will run with the fan as the furnace/AC tries to reach the desired temperature set point.

    2) If the system is NOT calling for heat/cool, but the humidity set point is higher than the current humidity, the ecobee Smart (which I'm going to start calling the Ecobee 1) will run the fan and humidifier only in an attempt to reach the humidity set point.

    Note: If, during #2, the temperature or time changes so that heating or cooling is called for, the humidifier will stay on with the fan as it heats/cools, and still attempt to reach the humidity set point while the furnace/AC tries to reach the temperature set point.

  • EFTCEFTC AB, CanadaMember

    Is it possible to wire the Ecobee 3 thermostat to the humidifier? If yes, can you prepare a DIY guide just like the one you have for the Ecobee 1 thermostat? Thanks.

  • SteveSteve Seattle, WAAdministrator

    EFTC said:
    Is it possible to wire the Ecobee 3 thermostat to the humidifier? If yes, can you prepare a DIY guide just like the one you have for the Ecobee 1 thermostat? Thanks.

    It's totally possible... but only if you have 2 "spare" wires available in your wire bundle that runs from your HVAC location to your thermostat. But I will definitely be updating new how-to versions over the next few weeks/months when the ecobee3 starts shipping. :)

  • karlmayerkarlmayer Member
    edited October 2014

    Steve said:

    EFTC said:
    Is it possible to wire the Ecobee 3 thermostat to the humidifier? If yes, can you prepare a DIY guide just like the one you have for the Ecobee 1 thermostat? Thanks.

    It's totally possible... but only if you have 2 "spare" wires available in your wire bundle that runs from your HVAC location to your thermostat. But I will definitely be updating new how-to versions over the next few weeks/months when the ecobee3 starts shipping. :)

    What if you only have 1 spare wire, Steve? Would using the Ecobee3 'Internally powered wiring' diagram and a relay to separate the 24V solenoid from the furnace make 1 wire work?

  • chrisyngchrisyng calgaryMember

    I'm running a honeywell 224 humidifier that utilizes a 24V solenoid. I have 1 wire from the solenoid connected to the "C" terminal on my furnace board, and the other wire of the solenoid connected to the AUX+ terminal of the ecobee. This controls my humidifier just fine.

  • Thanks, chrisyng; exactly what I wanted to know.

  • EFTCEFTC AB, CanadaMember

    I have a drum type humidifier. Do you think it will work?

    Currently it is powered by a separate 24V transformer coming out of the furnace.

    I worry that if I wire it via C terminal and + terminal it might overload the furnace electronics.

  • SteveSteve Seattle, WAAdministrator

    chrisyng said:
    I'm running a honeywell 224 humidifier that utilizes a 24V solenoid. I have 1 wire from the solenoid connected to the "C" terminal on my furnace board, and the other wire of the solenoid connected to the AUX+ terminal of the ecobee. This controls my humidifier just fine.

    Yep - Chris beat me to it. As long as one side of the 24V solenoid is connected to a COM terminal (whether at the thermostat or on the furnace control board), then you only need one additional wire on the AUX+ side.

  • my0gr81my0gr81 coldnadaMember

    I have a Waite 6000 with one of those built in digital controller and the useless humidysense sensor on the bypass side. Any way to jury rig this to use the ecobee3's accessory ports? I can run a wire to the furnace if needed and also have a spare HUM connection on the board. Any help appreciated as I looked at all the other diagrams, and they all expect to sub for an analog humidistat.

  • EFTCEFTC AB, CanadaMember

    To my0gr81: If i am correct, all you have to do is connect the wires from water solenoid to the AUX terminals on your E3.

    Alternatively, you can run a relay from your E3 and use it to turn on the Wait 6000. With this setup, just run the 2 wires from the water solenoid to the power supply and wire up the relay so that it when the AUX terminals on the E3 is energized then the relay will turn on the power supply.

    my0gr81
  • my0gr81my0gr81 coldnadaMember

    Thank you, I was thinking about that, but good to have confirmation about my thoughts.

  • my0gr81my0gr81 coldnadaMember

    l> EFTC said:

    To my0gr81: If i am correct, all you have to do is connect the wires from water solenoid to the AUX terminals on your E3.

    Alternatively, you can run a relay from your E3 and use it to turn on the Wait 6000. With this setup, just run the 2 wires from the water solenoid to the power supply and wire up the relay so that it when the AUX terminals on the E3 is energized then the relay will turn on the power supply.

    All right, I thought a little more about this? Will the E3 supply enough power to trigger the selenoid? or should I go HUM to selenoid and Acc+ from the E3 to the other end of the selenoid? If I do that, will the E3 detect the equipment as there would not be 24v on Acc+ until a heat cycle kicks in. I knew, I was missing something or need to learn more about this.

  • Steve - thank you for this post and for the more detailed version on your blog. I just picked up an Ecobee3 bundle (came with a few remote units) and connected all of my heating/cooling to the unit AND connected an older Aprilaire 440 unit using the basic instructions you provided (did not link Rh to Acc1 as I don't think this is necessary with the E3). The Aprilaire needs a new solenoid but once that is replaced I'll let folks know how the install went!

  • SteveSteve Seattle, WAAdministrator

    I just did this with an E3 this weekend. Writing a blog post now.

  • EugEug ChicagoMember

    @Steve said:
    I just did this with an E3 this weekend. Writing a blog post now.

    Has the post been taken down? I can only find the E1 wiring on the blog.

  • @Steve where is the post? I want to wire my trane humidifier to my E3. :(

  • carinyacarinya bellefontaine OHMember

    @Steve said:
    I just did this with an E3 this weekend. Writing a blog post now.

    Do you have a link for the post ?

    Aprilaire 400 arrived today ..... : )

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