Nest 3 + Heatpump/Electric Aux + Airking(Wait) 18Gal Humidifier

Old 02-23-18, 12:05 AM
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Cool Nest 3 + Heatpump/Electric Aux + Airking(Wait) 18Gal Humidifier

I'm just posting this because I searched high and low and couldn't find this exact setup for the nest. I saw things about relays and other wiring diagrams. I ended up just winging it sorta and got it to work perfectly so I thought I'd share what worked for me in case anyone else is trying to do this.

I was switching FROM a Lennox thermostat to the Nest 3rd Gen.
The Humidifier had the newer humidistat which is digital and was powered inline to the Humidifier.
Essentially... Power adapter in wall... spliced cable into the humiditat and the two connectors on the other side of the splice to humidifier to power it. I ended up just rejoining the cable to make a standard power adapter and shelved the humidistat.

First my previous thermostat wiring.

My final Nest Wiring (anything not used from previous was just capped or removed. T1 and jumper)

For me I have drop ceiling in the basement just below the thermostat. I went and found the big brown thermostat wire leading to the furnace between the furnace and the thermostat. I killed the power to it and then skimmed the main wire open to reveal the little ones inside.

I found the black (C) wire and severed it. Then found the brownish purple (T2) wire and severed it (capped the end that was coming up FROM the furnace)

I got a piece of spare thermostat gauge wire (just two smaller cables inside, red and white). cut a length that would reach the humidifier from where I spliced into the thermostat cable. Skimmed the thermostat ends and pushed them til they clicked into bypass terminals 1 and 2 on the solenoid piece. The other end of the wire, terminal 1, I used a cap to join it with(and rejoin) the black C wire from the thermostat cable.

The other wire from terminal 2, I used a cap and joined it to the brownish purple (T2) wire on the side coming down FROM the nest. Make sure all dip switches on the Humidifer are in the ON positions. Plug the adapter for the humidifier directly into the wall for standard power.

Powered Nest and furnace back up. Everything works as expected. Nest turns the green light on and water flows when its humidifying. You gotta go into the Nest settings and set the * to Humidifier.

Hopes this helps someone.

Last edited by carverstone1; 02-23-18 at 12:47 AM.

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