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Can't get humidifier to work with Ecobee3

therivieratheriviera Member
edited November 11 in ecobee

Hi -

My home is new construction. Furnace is York, Humidfier is Honeywell HM700. We have 2 zones - one upstairs (zone 1), one downstairs (zone 2).

I'm getting a blinking yellow light error (3 times, which means there is no current to humidifier unit) on the humidifier. I spent a while on the phone with Ecobee and as far as they can tell, wiring is correct. However, they think that because the humidifier is not wired directly to the ecobee (rather it goes through the furnace) the ecobee cannot call for the humidifer.

We are in a small town and there is only 1 guy that knows how to install humidifiers and he's out of town. Would appreciate any help we can get!

Here are pictures of the wiring:
This is where the humidifier R/HUM connects to the furnace control board (yellow wire, goes to R on furnace control)

HUM from Honewell humidifer (blue) is wired to this yellow wire, which goes to Ecobee Zone 2.

Furnace control board to Ecobee Zone 1 and 2:

Humidifier wiring:


  • Ok, so based on reading the main Ecobee 3 thread I switched the power wire (red) from Rc to Rh where it had originally been. We only switched on the advice of the guy we spoke to at Ecobee. So now, instead of blinking yellow, it's blinking green. Which means that the humidifier is working but it's not getting a call from the ecobee.

  • kevinmcckevinmcc Macomb, ILMember

    I suspect the wiring is wrong.

    1 R/HUM is power from the humidifier unit.
    2 HUM is to call for humidity.

    They should connect to Ecobee3 ACC+ and ACC- of the Ecobee3 that you want to control the humidity.

    There is a note that says the following in the install manual.

    NOTE: If a Prestige, VisionPRO, Lyric (or similar) are used to control humidity, wire the two HUM contacts to terminals 1 and 2 on the HM700. With the jumper in place between terminals 1 and 8 on the HM700, only these two wires are necessary to control humidity. Be sure to configure the control to force fan on with a call for humidity, or run on a heat cycle if the fan enable wiring is not used.

    You may need to a jumper from 1 to 8.


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