Generalaire humidifier with nest 2.0

Hi, I have carrier furnace, generalaire humidifier, want to install nest 2.0.

Current setup, humidistat with two wires, one going directly to humidifier solenoid, other wire going to a transformer or switch (I'm not sure what it is), then goes to solenoid. On back of transformer, there are two wires, black going to furnace EAC-2, white going to furnace EAC-1.



This is the picture of the switch/transformer? The orange wire goes to the humidistat & the black wire goes to the humidifier solenoid. Just for your reference.

I want my nest 2.0 to control my humidifier as well, after I disconnect the two wires from the humidistat, can I hook the one directly from solenoid to * & the other one to C? Or would I need a relay switch or some other wiring config?

please help!!

 

The photo is the transformer.

Those won't be used anymore, so wire solenoid to * and C.

 

Thanks, just to confirm, I should do the following?

One wire from * to solenoid on humidifier
one wire from solenoid to C on furnace or C on nest thermostat?
take out the transformer & unplug the transformer wires from the EAC-1 & EAC-2?
Do not use The 2nd wire from humidistat? Or should I connect this 2nd wire to C on nest thermostat?

 

Wire the one wire to the c on the furnace.

Take out the transformer, and humidistat.

Fi you don't have C wired on the Nest now, wire it up to the furnace.

 

Okay, thanks, one last confirmation.

Wire from thermostat * to ssolenoid
Wire from solenoid to C (Com24v) on furnace
Wire from C (labelled Com24v on furnace) to C on nest thermostat (currently no wire connected to C on current thermostat)

this correct?

sorry I just want to make sure I'm doing it all 100 % since I've traced all the wires.

thanks again, u guys are awesome. I'm just waiting for paint to dry on patch then will be installing it.

 

Yes, that is correct. Let me know if you have anything else.

 

Just reporting that I installed the Nest thermostat as per your instructions, and everything seems to be working fine. The thermostat is running my humidifier right now until it reaches minimum threshold that I've preset. Will see if it will auto turnoff by the morning. The fan is going but the furnace is not to move the air from the humidifier. I tested the furnace by turning up the temp earlier and that worked as well. Will have to see how it controls the a/c in the summer. Super happy camper right now!!

The install couldn't be any easier once u know where the wires go. Glad I didn't fork out the $119 they wanted for the concierge service. Actually while I was waiting for a response from the forum earlier today, I called Nest technical support, waited for 45 minutes, and the girl told me my nest wouldn't work with my humidifier because it had two wires from the old humidistat. Glad I didn't listen to her!!

Thank you for all the expert advice, wouldn't have been confident doing the install without you confirming what to do. So straight forward once you know what you are doing. You guys are awesome!!

 

I found it really helpful. I have a different heating unit which is Lennox and BeatAir humidifier. But my original setup looks almost same. My transformer was connected on HUM contact of furnace board and the white wire to white base contact don't remember exactly. So it sounds like I can wire my solenoid one wire to * on my NEST and second wire to what? "C" on control board and run wire to "C" on NEST.
My main goal is to be able to turn solenoid when fan is ON and furnace is in heating mode. Because now it is only "ON" when heater is kicks on and that time is not enough to humidify air.

 

Yes, wire it just as you put it on your post.

 

Jay -- I have the same Carrier furnace and General Aire humidifier as Sam ... if I read your instructions correctly ...

Nest * ==> Solenoid
Solenoid ==> Com24v on furnace

Is the additional wire from Com24v on furnace ==> Nest C required ?? or optional -- just asking because I have shortage of available wires to Nest ...

Let me know if you can -- thanks!

 

That is correct.

Nest says you don't need a common wire... Give it a try...

 

Thanks Jay ... it works perfectly ... I love the humidifier control ... and the "Humidifying" capability of the Nest is fantastic -- it runs the fan with the humidifier even when heat is not required ...

Having the humidistat upstairs versus in the cold air return of the furnace (in the basement) is far more accurate.

I would swear the air quality in the house is better and it just feels warmer on a regular basis ...

Thanks !!!

 

Glad to hear it's working, but I am not a fan of running it alone with fan only since a lot of water is wasted this way. There's no heat to help evaperate the water off the pad faster.