UZC4 + 4 Nest Thermostats + 1 (New) Humidifier

Post your questions and comments here.
Post Reply
Posts: 1
Joined: Sat Feb 04, 2023 5:24 pm

UZC4 + 4 Nest Thermostats + 1 (New) Humidifier

Post by EKobres »

I have an existing UZC4 installation with 4 Nest (2nd gen) thermostats.

All of the Nests have an available extra orange wire that could be connected to the "*" terminal to control a humidifier or dehumidifier or other accessory.

It looks like the UZC4 has all of the circuitry and logic to handle an Aux connection from a zone to call for humidity through the Aux relay.

Assuming all the nests are configured for "normally open" on the "*" port, and since the Nest handles the call for heat or fan in conjunction with the call for humidity, is there any reason to not simply wire all 4 "*" wires together and into the Aux connection by Zone 1? Is the Nest simply closing a relay between R and "*" to call for humidity?

It seems like this should work, but I don't want to fry any of the Nests by making a bogus assumption about providing a path for R to the "*" of a Nest that's not actively calling for humidity.

Thanks in advance for the help and advice!
Steven W.
Posts: 112
Joined: Tue Jun 25, 2019 9:13 am

Re: UZC4 + 4 Nest Thermostats + 1 (New) Humidifier

Post by Steven W. »

Give me a call when you get a chance and I will walk you thru this setup

Steven R. Weisneck

HVAC Zoning Technician
Tel: (732) 446-3110 Ext. #461
M-F 8:00am - 4:30pm
Steven R. Weisneck
Technical Engineer
Tel: (732) 446-3110 Ext. #461
Post Reply