Thermostat U1 Wire

Hi community. My house is a month away from finishing and I would like to put in two Wyze Thermostats. I spoke with NEST, showed them my wire configs (as attached below) and they verified it would work. When I did the Wyze Thermostat compatibility checker, it did not show a selection or port for my U1 wire that I currently have in my dumb thermostat that comes with the house.
*all of the other wires I know are standard and look ok.

Anyone have any idea what I would connect the U1 wire with?

U1 typically controls either a ventilation or humidifier/dehumidifier but you should trace it to your control board to be sure. On a few occasions I have seen them wired to a heat/cool stage on a heat pump system.

Or check with an HVAC person.

Welcome to the Wyze community @daverosen5!
When you do the compatibility test, select the “I don’t see all of my terminals” then choose”other”.

Where does it show more info on “The thermostat can control 1 humidifier.”?
Looking at the install config video, I do not see a spot for U1 with the Wyze Thermostat.

The thermostat may not be compatible with your system. I’ll tag the expert,@Chuan to see if he can help you.

Thanks Brlepage. Looking forward to it @Chuan.
One thing to note, the upstairs AC does not have a U1 wire, only the downstairs.

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Do you have a humidifier or other external piece of HVAC equipment? Where does the wire go?

U1 wire should be placed in our * terminal, it is a not very common terminal so we did not have it in our checker, but we consider to add it if there are more cases appearing.

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I’d recommend putting this information in the comparability checker and/or the the setup guide.

Wonderful, will install when I receive it in December and will put the U1 brown wire in the * terminal.

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So mine has a brown and orange wire going into U1. I know I can put one of them into * section but what about the other one?

I have the same thing going on over in Texas. Two U1 terminals. One goes in * but What about the other @Chuan can you help us out? Thanks in advance!

Might need a pigtail to wire them both to the same * connector if they are running 2 separate devices. This is the problem with lever style thermostat hookups, if you need to connect 2 devices to one terminal, you have to use a pigtail and wirenut, and hope that the relay in the thermostat can drive 2 devices.

Did this connecting two U1 wires on old thermostat into one * terminal work?

Hello, anybody can help me on where to connect the two cables connected to two U1 terminals of my Honeywell to the new Nest?

I have the same problem and don’t have idea where to connect them.

I have the same issue. Was there a final solution to this dual U1 problem?

u wires are the same as aux or star… you need to know what devices they are controlling (usually a humidifier or dehumidifier, or air cleaner)