I am looking for advice on how to wire my new humidistat with my furance and humidifier. First, here are the components I'm working with:

  • Furnace: Carrier WeatherMaker Infinity (Model 58MVP100 14120)
  • Humidifier: Honeywell HE265B1005
  • Humidistat: HoneywellH6062

Background: Old humidistat (Honeywell H1008A) quit working so ordered this new one. The humidifier is a Bypass, with both humidistat and humidifier mounted on the Return side. Humidifier is hooked into COLD water line.

What I'd Like: Since humidifier is on Return side and hooked into cold, I'd want the humidifier to kick on when humidity reads low and there is a call for heat. (Feel free to let me know if you feel differently).

Where I am at in the setup: I do have the humidistat hooked up to constant 24V and the Outdoor Sensor hooked up and tested.

What I need help with: My furnace does have a 24V HUM terminal which kicks on during call for heat, so I know I can use that, I just need to know how to hook it in. On my humidistat I have two U terminals for the humidifier, and I need to know how to hook those up to the furnace and humidifier solenoid. I will post some pictures. I know the bottom U humidistat terminal gets wired to one of the humidifier solenoid wires. The top U terminal is what I need help with....and then I need help with what wire to hook into the second humidifier solenoid wire. One note, my furnace does have the HUM 24V terminal, as well as a HUMR (HUM relay) terminal. enter image description here enter image description here enter image description here

  • Seriously nice job for your first post! I removed "first post" because we can tell, but nobody much cares :), and I tweaked the formatting a bit for readability (click the link above my name and you can see the changes I made so you know for the future). While you're waiting for an answer (I don't have one for you), you can take the tour and browse the help center so you can learn how this Q&A forum differs from most general discussion boards so you can make the most of it. Welcome!
    – FreeMan
    Commented Feb 26, 2021 at 18:05
  • 1
    Thanks, and thanks for the formatting assist!
    – Nick
    Commented Feb 26, 2021 at 18:36

1 Answer 1


It goes "HUM -> U, other U->solenoid terminal, other solenoid terminal->C"

In order to get your humidifier to work, you need to create a closed circuit through the humidifier solenoid to bring 24VAC to it. Since we know the HUM 24V terminal is a 24VAC source from the wiring diagram you posted with the C terminal as its corresponding return, we can pull 24VAC from that and feed it to one U terminal on the humidistat. The other U terminal, then, connects down to one of the humidifier's solenoid connections; finally, the remaining terminal on the humidifier solenoid gets connected to the C wire on your furnace. The result is a closed circuit that only is energized when your furnace permits humidification and the humidistat calls for water, just as you wish it to work.

  • Thank you! I will give it a try today. Out of curiosity, do you happen to know what the HUMR (relay) terminal is meant for?
    – Nick
    Commented Feb 27, 2021 at 16:00
  • @Nick if it's a single terminal, then it's for a 120V humidifier connection Commented Feb 27, 2021 at 16:15
  • I was able to wire today (finally), using your recommendation, ThreePhaseEel...and I can confirm success! Thank you very much! Humidity level was low and a call for heat came through, and sure enough the humidifier solenoid opened up to let water soak the pad. Water shutoff once the call for heat ended. :)
    – Nick
    Commented Mar 1, 2021 at 4:30
  • @Nick -- we thank folks around here by upvoting and/or accepting their answers :) Commented Mar 1, 2021 at 12:37
  • Upvoted and accepted :)
    – Nick
    Commented Mar 1, 2021 at 15:10

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