Nest compatible Trane system?

[NedNix]

Aloha! I have a Trane heat pump. I had thought that the wiring would not be compatible with a Nest thermostat, because Trane likes to use a lot of proprietary gear. When I took the thermostat face off, however, I saw something that looked more like the typical six-wire setup. I am including photos below. I have two zone HVAC. My concerns are whether a Nest will actually work here and also that there appears to be some sort of bridge connecting the R & RC posts in the upper right corner. Is that something to be worried about? Lastly, would it matter if I got a regular Nest or a learning Nest? Can a learning Nest even work here? If I need to provide more info, let me know & I'll dig up what I can. Thanks for any help in advance.

[Patrick_Caezza · Accepted solution]

@NedNix 

Any Nest thermostat should work in your system. The Learning Thermostat works with the most system, and the Google Nest Thermostat is a bare-bones entry-level thermostat.

The jumper between the R and RC terminals is not needed with any Nest thermostat, as it will automatically jump the terminals together if needed.

Be sure to ensure all wires have a bright shiny looks to them and are straight. Also keep the bare length only long enough to properly sit in each terminal.

Try this wiring.

Your top picture

White - W1 to W2 or W (set as Aux heat)

Red - R to Rc or R (jumper not needed)

Orange - O to OB or */OB

Yellow - Y to Y1 or Y

Green - G to G

Black - B to C

Your bottom picture

Red - R to Rc or R (jumper to RC not needed)

Orange - O to OB or */OB

Yellow - Y to Y1 or Y

Green - G to G

Blue - B to C

The "or" is for the Google Nest Thermostat Wiring

[NedNix]

Thanks for the answer. I thought those were the wiring alignments, but I wanted some more experienced eyes on the current setup. It isn't obvious because the wiring is very cluttered, but in the second pic there is a white wire connected to the W1 port on the left side. It's hidden under the green wire. So, I can also connect it to the W1 terminal.

I think what I'll do is start with the zone that doesn't include my bedroom. That way if something goes wrong, I haven't shut down the cooling for the entire house just as summer kicks into high gear. When I'm comfortable that works, then I'll switch the other side. I'll do some research before deciding which thermostat to buy. The learning thermostat seems worth the money. I hadn't gotten that far since I wanted to make sure Nest was compatible first.

I'll post an update when progress is made. Again, thank you.

[NedNix]

I just installed the Nest thermostat. So far, so good. I have not added the temperature sensors that came with it, I'll wait until I'm more familiar with the thermostat & app to do that. Your wiring diagram was spot on. Of course, when I connected the face to the thermostat it showed the same wiring setup, only in pictorial form.

I made a mistake in my original post. It is not a heat pump. It has gas heat, however, the setup still works - at least for AC. I would think the heat will work as well, since the wiring setup matches the old setting.

The one hitch was that the face was more difficult to install than I thought it should have been. The Nest kept rebooting itself. However, after adjusting it a few times, it settled into place.

Right now, I have set the manual temperature range. I keep it on the heat & cool setting. If the temperature in my house in lower Alabama somehow drops below 60 in June, I want the heat to kick on no matter the time of year.

[Jenelyn_O]

Hi there,

Thanks for reaching out. I'm sorry for the delay. I'm glad to hear that it is working well. Please feel free to create a new thread if you have any questions or concerns, as we'll be willing to assist you from there. Otherwise, I'll be locking this thread after 24 hours. 

I appreciate your help, @Patrick_Caezza.

Best,

Jenelyn