Nest thermostat help, one works, second doesnt

[Rdozer]

Hello some help would be greatly appreciated I recently. I recently purchased a Nest learning thermostat and installed it downstairs. It works great so I decided to purchase another Nest Thermostat but not through learning version to install upstairs. I do have a zone system but when I try to install the nest thermostat upstairs it says that it is not compatible with my system, even though it has the exact same wiring as my thermostat downstairs. Could anyone give me a hand with what's going on? Thank you so much

[Patrick_Caezza]

Zone controlled system can be strange.

Post a picture of the thermostat's wiring here and post another of the zone controllers wiring and model too

[Rdozer]

https://photos.app.goo.gl/mtSY4yiVvjCVYzv7A 

The forum says I don't have permission to upload photos, but here's a link to a picture of the thermostat's wiring and the zone controllers wiring.

[Patrick_Caezza]

What told you it wasn't compatible?

From what I see, it is compatible.

Try this wiring

Blue - C to C

White - W to W

Yellow - Y to Y

Green - G to G

Red - RC to R (jumper to RH not needed)

The C wire on zone controllers sometimes isn't a real C wire and might cause a problem, but I don't think so here

[Rdozer]

That's exactly how I wired it up with the Nest, sorry if there was confusion there but that wiring  picture is of my old thermostat .

It was the Google Home app that was telling me it wasn't compatible. When trying to set it up in the app after wiring it up, it would ask me what wires I had. When I selected the wires I had, it would say your system is not compatible. I checked it 10 times to make sure I was selecting the correct wires too. 

I added a screenshot to that link that shows what wires I am selecting. It is weird because it doesn't have the exact wires I have, for instance I have a W wire, but the only option it gives me is W/W1. 

I know I'm selecting a the options here instead of the wires I have, but when I even only select the wires I have which would be... C, W, Rh, Rc, G and Y the app still tells me it's not compatible. 

[Patrick_Caezza · Accepted solution]

I see what the problem is. You only have one R wire, so only select R, not Rc and Rh. You also don't have the O or B wires.

All that you should have selected are W/W1, Y/Y1, G/G1, R, and C.

[Rdozer]

Ahh I see, I was trying to put in all the options my thermostat was giving me, not each physical wire that I have lol. At the top it said "these are some of the wires your system may use" and I took that as select all possible options haha. I will try to wire it up again when I get off work. Thanks for your help! 

[EdwardT]

Hi folks,

It's me again. I wanted to check back in to see if you have other questions and concerns. Feel free to let me know if you do. 

Thanks,

Edward

[EdwardT]

Hi folks,

Just checking in to make sure that you've seen our response. Please let us know if you have any other questions or concerns as I will be locking this in 24 hours.

Thanks,

Edward

[Rdozer]

Problem solved! Just an issue with selecting correct wires in the app. 

[EdwardT]

Hi Rdozer,

Awesome — glad to hear everything is back and working as intended. I will lock this thread now. Please feel free to create a new thread should you have some more questions or concerns in the near future and we'll be more than glad to help.

Thanks,

Edward

[MZellmer]

Have just conquered a two zone HVAC forced air system with two Nest Learning Thermostats.  The challenges I faced were (1) the lack of power (the C wire) and (2) the switching between heating and cooling.  I've posted elsewhere in this community a detailed post with photos and diagrams of my solution. Not sure whether it will solve your situation though.

[EdwardT]

Hi folks,

@Patrick_Caezza, thanks for the help!

@Rdozer and @MZellmer, how's it going with your Nest Thermostat? Still need our help?

Thanks,

Edward