Nest Gen 3 Thermostat Wiring

[Devinopie]

I have a 7 wire system on my current trane setup with a brown wire not in use in the back. Tried the nest app for set up and they say it needs more in depth research instead of easy plug and play. I don't have a gas heater that gets charged, guessing a heat pump under the house. I attached a pic of the current wiring. Which wires should go where? 

Red is RC, orange is O, yellow is Y, green is G, blue is B, white is W1 and black is X2. 

 

[Patrick_Caezza]

Give this wiring a try

Black - X2 to * (set as Emergency heat)

White - W1 to W2/AUX (set as AUX heat)

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

Orange - O to OB

Yellow - Y to Y1

Green - G to G

Blue - B to C

[Devinopie]

So this is what they gave me via support 

Yellow - y1

Green - g

Orange - o/b

Red - rc

White - w1

Black - *

[Patrick_Caezza]

They just left the blue (B) wire out. For this thermostat, the B is the C wire.

You can verify by looking at the terminal block on the control board in the furnace/air handler.

With this being a heat pump system, the white (W1) wire is for the Aux heat and the W2/AUX terminal on the Nest is the correct location for it.

[Devinopie]

Sorry, blue is c on mine too. So you're saying take the white from w1 and place it in w2/aux?

[Patrick_Caezza]

That is my recommendation.

[Ryan_G]

Hi Devinopie,

Thanks for reaching out here in the community.

I'd like to jump in here and check if you've seen Patrick_Caezza's response about his wiring configuration suggestion. Let us know if you tried it and how it is going.

Thank you for your help, Patrick_Caezza.

Best regards,

Ryan

[EdwardT]

Hi folks,

It's us 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

[MelbaDT]

Hi, 

We haven't heard from you in a while so we'll be locking this thread if there is no update within the day. If you have any new issues, updates or just a discussion topic, feel free to start a new thread in the community.
 

Best, 

Melba

[PilotKinw]

Not sure if you're still answering questions on this, but I have an American Standard Heat Pump, installed new in Summer of 2017.

The thermostat that came with the unit works fine.

But Oregon was offering the Nest Learning Thermostat for $25 and I couldn't resist.

I've installed it, and made sure it's wired correctly, I even have the wiring diagram from the HP to reference and I'm relatively sure I have it right. 

No cooling. 

I've double checked the wiring, and replaced the old thermostat and the cooling works fine.

Any suggestions?

TIA

Terry

[PilotKinw]

So, I'm going to reply to my post here, since I figured out what was wrong, and maybe it will help someone.

I reinstalled the Nest Learning Thermostat, and on a hunch, I reset the whole system for defaults. Then I started the app, selected the bar code, and did a new device setup.

This time, I told the Nest that it used the O (orange) wire, that goes to the compressor as I understand it, instead of the blue wire.

Started the system and did a cool test, and cool air came on.

So, in the end, in my case, it helped to do a reset after switching wires around.

[MelbaDT]

Hey folks, 

Sorry for the delay here. 

PilotKinw, thanks for  chiming in and for keeping us updated on what you've done to resolve your concern. We're glad to hear that your thermostat is now working as it should with your HVAC system. 

Devinopie, the W or W1 wire controls your heating system while W2 wire can control different types of heat based on the type of system you have like different stages of heat, auxiliary heat, or dual fuel. Take a look at this link for more detailed information: https://bit.ly/3nEpkMy

Best, 

Melba

[MelbaDT]

Hey Devinopie, 

It's me again — I want to ensure that everything is covered here. Let us know if you have further questions. 

Best, 

Melba

[MelbaDT]

Hi, 

We haven't heard from you in a while so we'll be locking this thread if there is no update within the day. If you have any new issues, updates or just a discussion topic, feel free to start a new thread in the Community.

Best, 

Melba

[Devinopie]

So when I tested the system as before, everything seemed to work fine. I'll try w2 aux instead of w1 and see if it works well. Can anyone tell me the difference between the wiring the two ways then? Thanks again!