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Aprilaire humidifier Controls

I have a Honeywell T10 thermostat, it can control a humidifier. It uses 2 wire U terminal. I would like to install the Aprilaire 865 unit as my house has no ductwork. I notice install instructions thermostat uses 4 wires. What would be required to get this working off of the Honeywell Thermostat, I'm assuming some sort of simple relay. I attached the instruction wiring page.

Comments

  • ratio
    ratio Member Posts: 3,031
    You want to land the U terminals on the "HUMIDISTAT" terminals on the humidifier. Do not install any jumpers at the thermostat, you do not need the 24 VAC coming from the humidifier ("Tap Connectors" on the schematic) either.

    Double check the programming of the U relay, I'm not certain but I suspect it needs to be set to normally open, close to humidify.

  • pmarinello489
    pmarinello489 Member Posts: 13
    So your saying I would only need the two "H" wires straight from the humidistat to my U terminals and don't need that 24VAC transformer connected to anything? Simple...
  • ratio
    ratio Member Posts: 3,031
    Right. The H wires are the command to the humidifier. The other two wires from the humidifier are power for the humidistat, but the Honeywell is already powered (I assume!), so we don't need them. The U terminals are a dry contact (they don't provide power) that can be configured for humidifier control, just like we want.
  • pmarinello489
    pmarinello489 Member Posts: 13
    yes. yes I see thank you so much. Very simple.
  • ratio
    ratio Member Posts: 3,031
    Your welcome.

    Post back after a while & let us know how it's working. Or if, I suppose. :wink:

  • HVACNUT
    HVACNUT Member Posts: 4,355
    Make sure the U Slider Tab is down on the T10.
  • pmarinello489
    pmarinello489 Member Posts: 13
    I am just gathering my information for now, Winter is almost over so my humidity levels are going to rise but when I do start my basement work in a few months I know what I am doing!
  • pecmsg
    pecmsg Member Posts: 2,564

    I am just gathering my information for now, Winter is almost over so my humidity levels are going to rise but when I do start my basement work in a few months I know what I am doing!

    You don't need a "Humidifier" in the summer months just the winter.
  • HVACNUT
    HVACNUT Member Posts: 4,355
    > @pecmsg said:
    > (Quote)
    > You don't need a "Humidifier" in the summer months just the winter.

    He knows that already. It's part of a basement project. Next winter is almost here.
  • pecmsg
    pecmsg Member Posts: 2,564
    HVACNUT said:

    > @pecmsg said:

    > (Quote)

    > You don't need a "Humidifier" in the summer months just the winter.



    He knows that already. It's part of a basement project. Next winter is almost here.

    Then that begs to ask Without Duct work how is a basement humidifier going to help?
  • HVACNUT
    HVACNUT Member Posts: 4,355
    > @pecmsg said:
    > (Quote)
    > Then that begs to ask Without Duct work how is a basement humidifier going to help?

    That model has an integrated fan pack for air distribution.
  • pmarinello489
    pmarinello489 Member Posts: 13
    Thank you... haha