I need wiring help on my Nest thermostat

[rgaila]

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Original Poster: Brian Wallace 1059 

I'm not sure how to wire 2 additional wires I have on my thermostat. I need help with the red U1 wire and the brown U1 wire. I think the U1 wire is a jumper between U1 and R. See the attached image for the wiring in my current Honeywell thermostat. 

[rgaila]

Hi Brian,

Thanks for reaching out and welcome to our community! It's great to see that you're making your home a Nest one. We're happy to help assist in setting up your new thermostat.

It looks like your U wires hook up to some sort of air quality equipment (e.g., humidifier or dehumidifier), and it's hooked up to your R wire, which powers your heating and cooling system. Don't connect any jumper wires to the Nest thermostat. (Here's why.)

At a glance, you might not need to mess with either the red/brown U1 wires. However, since we don't know the specifics of your particular Honeywell system, it's advisable to contact a Nest Pro as you have a dual-fuel system--which are notoriously difficult to wire with Nest thermostats (the E can't altogether). Using this article on identifying your thermostat wires might also help for your consult.

Hope this helps! Let us know if you have any other questions for us.

-From Garrett DS, Community Specialist.

[Carolinastylin]

Brian did you ever resolve this issue? I have the same problem.

[cmcphee]

Same here - would love to know. I have an Aprilaire 800 series humidifier and just not sure where to put those two wires in the nest