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Ecobee3 + Aprilarie 600A humidifier.

I just got my ecobee3 installed and I decided that I wanted to run my humidifier off of it. I only have 18/4 wire running down to the furnace so I will need to run a new length of 18/5 cable. My question is since I will have enough wires I have options on how to run the humidifier, would it be better to wire the humidifier's solenoid valve up as not externally powered (acc+ and acc-) or externally powered (acc+ and com)?


  • jobar730jobar730 DenverMember

    I don't beleive it matters. I have mine wired as external powerscource using the afc+ and acc-and works. Just have to set the humidifier toe to steam. Evaporative type only runs when heat is call for.

  • sgibbers17sgibbers17 Member
    edited January 2015

    I found out that the 600A has a solenoid valve that is 120v AC along with the transformer that came with the humidifier (I'm guessing that the "A" is for AC). Witch is odd that it transforms 120v AC to 120v AC but that is how it is labeled and what my multimeter says, along with the valve. Since the valve is designed to run off of 120v the thermostat will not control it. So many bought a replacement 24v DC valve that comes in tomorrow.

  • fpuigfpuig East CoastMember

    I installed an Aprilaire 600m in my HVAC and the solenoid valve is 24vAC, so I wired it one lead to the E3 (ACC+) and the other to the C terminal on the HVAC control board. It is working fine for 1 week now. The A means that it come with the "Automatic" control. The M model come with the manual humidistat.

  • sgibbers17sgibbers17 Member
    edited January 2015

    OMG, I can't believe I did that. I guess when I saw VAC I assumed it meant 120VAC and when I read my multimeter I just thought I saw 120V. I also assumed that 24V was DC and not AC.

    I'll have to try rewiring it to com and ACC+ to see if that works. I had tried it both ways but that was before I requested ecobee to update my Firmware, now I am on the latest version

    So far the only way I have tested the humidifier is using the test function on my ecobee3 but it only turns the fan on when I select humidifier on. Is the fan supposed to start or is it only supposed to open the humidifier valve?

    My current wiring setup is

    On EB3 (RH, C, G, Y1, W1, ACC+, ACC-)

    On Furnace (R, C, G, Y, W)

    Humidifier Solenoid (ACC+, ACC-)

  • fpuigfpuig East CoastMember
    edited January 2015

    @sgibbers17; The easy way to know if the solenoid is DC or AC is looking at the wires, if the wires have (+ or -), could be red or black, it's DC. If both leads have the same color its AC. I'm not an expert on the HVAC industry but I think 24vAC is the standard.

    After updating the firmware, try connecting the solenoid leads (should be both yellow) one to the ACC+ and the other to the C point. Then make the changes in the thermostat and (reboot it). Make sure you turn ON the humidifier. You can do it through the ecobee portal, Go to System > Humidifier and select ON or Frost Control.

    Also when you turn it on through the test menu it should turn on the fan & the humidifier at the same time.

  • I got on the phone with EB Support today and talked to 3 people moving up the chain and we were able to get it to work. In the end I have one lead of the solenoid valve wired to the ACC+ and the other lead to C on the furnace. I can't tell you how many times I have tried this setup by my self and how many time I tried it with EB on the phone and it didn't work. I going to chalk it up to gremlins.

  • rathrboutsiderathrboutside Member
    edited January 2017

    Hi sgibbers17. I have my aprilaire wired exactly like your last post and my humidifier solenoid is not turning on when the ecobee3 says it is. Ugh... not sure what I'm doing wrong (I just posted this question if you look at my profile, it has my system setup). Any tips from support when you got your humidifier working? Thanks!

  • rathrboutside, there are 2 ways to to hook up the humidifier. The first way to have the solenoid hooked up with ACC+ and C on the thermostat. I was unable to get it to work this way but it may work for you. The other way is to hook one lead to ACC+ on the ecobee and the other lead to C on the furnace. But like I said in the last post I was not able to get either way to work multiple times until it just worked. I don't know what finally made it work but it does now. Try giving ecobee a call they were very helpful with me.

  • sgibbers17, thanks for the reply. I'm on the phone with support now and they are the are telling me to dry contact my Rh and ACC+ wires behind the ecobee3 and see if my humidifier turns on. I'm going to try that and wire the old manual humidistat back up to see if the solenoid is still working. My wires have a few splices and wire nuts on them, so I'm also thinking about running new ACC+ and C lines from the humidifier. I wonder if the ecobee3 is the problem though, not sending 24v correctly down the ACC+... who knows.

  • kevinmcckevinmcc Macomb, ILMember

    If you do end up running different wire, consider run 18/7 or 18/8 so in future you have extra wires if you need.

  • thats what I did I ran 2 18/5 wires so I have 10 total

  • Update (copied from other discussion): 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.

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