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Google Nest Thermostat wiring diagram

Gianna2009
Community Member

Can i use a Nest Thermostat with my current wiring ( R, Rc, Yellow, White, Green ) or do i need a Smart Nest Thermostat?

34 REPLIES 34

Jhonleanmel
Community Specialist
Community Specialist

Hi Gianna2009,

Thanks for reaching out. I'd love to know more about this. Could you share a photo of your current thermostat's wiring? Also, you could try our compatibility checker to see if your current system is compatible with the Nest Thermostat.

Thanks,
Mel

Hey Gianna2009,

Checking back in should you still have some questions here. Let us know by replying to this thread. 

Best, 
Mel

Hi Gianna2009,

Just one quick final check in here since activity has slowed down. We'll be locking the thread in the next 24 hours, but if you still need help, I would be happy to keep it open. If there's more we can do, just let me know.

Thanks,
Mel

HoneyWell that has a Yellow, White, Green, R and Rc wire. Which model should I purchase?

Jhonleanmel
Community Specialist
Community Specialist

Hi Gianna2009,

 

Could you confirm if you have a jumper wire from your R and RC wires? If so, you can get the Nest Thermostat or Nest Thermostat E. If there are no jumper wires, you can get the Nest Learning Thermostat.

 

Best,

Mel

I have a gold/copper metal staple on my current HoneyWell thermostat between the R and Rc wire. How would the Nest handle this? How would they connect?

Thank you

Gianna

Jhonleanmel
Community Specialist
Community Specialist

Hi Gianna2009,

 

That is a jumper wire. No need to use that when installing the Nest Thermostat.

 

Best,

Mel

Thank you, but where does the R wire and Rc wire attach to?

Jhonleanmel
Community Specialist
Community Specialist

Hey Gianna2009,

 

Where is the wire connected to without the jumper wire?

 

Best,

Mel

1 red wire is attached to R and the other red wire is connected to RC

Jhonleanmel
Community Specialist
Community Specialist

Hi Gianna2009,

 

Could you share a photo of your wiring?

 

Best,

Mel

image.jpg

 this is the wiring of the thermostat I want to replace. It has 2 red wires (R and Rc) which Nest model should I buy. 
the basic Nest doesn’t have room for 2 red wires, or is there another way to wire it?

Thank you

Gianna

Markjosephp
Community Specialist
Community Specialist

Hello there,

 

I wanted to stop by and see how I could help.

 

Thanks for helping, Mel.

 

@Gianna2009, Some HVAC systems, called dual transformer systems, use separate power sources for heating and cooling (Rc and Rh). If you have both power wires, you have a dual transformer system. The Nest Learning Thermostat 3rd generation, would be compatible with your system. You can also check your system’s compatibility before purchasing a Nest Thermostat with our online compatibility checker.

 

Feel free to let us know if you have more questions.

 

Regards,

Mark

I have R and Rc wires? 

should I still get the nest Learning thermostat? What ports should I connect the above wires to?

Markjosephp
Community Specialist
Community Specialist

Hello Gianna2009,

 

Here's a sample wiring diagram I created for the Nest Learning Thermostat. This is how the wires should be labeled from your thermostat.

 

Please let me know if that helps.

 

Thanks,

Mark

Thank you, this is helpful. I have a total of 6 thermostats. 1 for AC, 1 for AC/Heat, and 4 others to adjust temperatures in each room/area. Do I need a power connector for each one?

2 say to add C wires?

Markjosephp
Community Specialist
Community Specialist

Hey there,

 

Most of the time, Google Nest Thermostats can use the heating and/or cooling wires to charge their internal battery. To reliably supply power to the thermostat, you might occasionally need to connect a common wire, often known as a "C wire," or the Nest Power Connector. Do you have a zoning system? I found an article to learn more about Zoned system compatibility with Nest Thermostats.

 

Feel free to let us know if you have more questions in mind.

 

Regards,

Mark

Yes. I have 6 zones

Markjosephp
Community Specialist
Community Specialist

Hello there Gianna2009,

 

Thanks for confirming. In this case, the Nest Thermostat needs the Nest Power Connector or a common or "C" wire connected to provide power. If you have extra wires connected to your control board, you can use them as a backup, or better yet, contact a local technician or a Nest Pro to install.

 

I hope that it helps.

 

Best,

Mark

Just to clarify, I need a power connector for EACH thermostat? Please confirm.

Thanks for your help.

Markjosephp
Community Specialist
Community Specialist

Hey there,

 

Depending on the zoning system you might have, To be sure, could you also send us a picture of your zoning panel, showing where the wires are connected? There are cases where there are no C ports to connect a common wire, and a relay might be needed to support it.

 

I'll look forward to your response.

 

Thanks,

Mark

Markjosephp
Community Specialist
Community Specialist

Hey there,

 

Depending on the zoning system you might have, To be sure, could you also send us a picture of your zoning panel, showing where the wires are connected? There are cases where there are no C ports to connect a common wire, and a relay might be needed to support it.

 

I'll look forward to your response.

 

Thanks,

Mark

image.jpg

This is my zone wiring. I’ve purchased 4 nests so far and 2 keep alerting low battery and No wifi. Do I need charging connectors on everything?

Hello. It looks like I need 2 Nest power connectors since I keep getting alerts on the thermostats. I have changed batteries multiple times on each but they only last a few days. Very frustrating since this never happened with my old thermostats.

I was told there may be a free offer for them?
Please advise if possible.

Thank you 

Gianna

 

Markjosephp
Community Specialist
Community Specialist

Hello Gianna2009,

 

I'm sorry for the late response. I know it has been a while, but I wanted to ensure that everything was covered here.

Changing the batteries is only applicable for the Nest Thermostat 2020 model, which most likely requires a C-wire or a Nest Power Connector to work. With this, one free Nest Power Connector is available per household. Did you get this prompt during the setup in the Google Home app?

 

Thanks,

Mark

 

Gianna2009
Community Member

No, I never got the prompt during set up.

-Gianna

Markjosephp
Community Specialist
Community Specialist

Hey there,

 

During the setup, the Google Home app would provide a prompt about a Nest Power Connector or a C-wire if you needed one. To confirm, could you please check its power information in its "Equipment" settings?

I'll look forward to your response.

 

Thanks,

Mark

Gianna2009
Community Member

Looks like I need a Nest power supply adapter or C-Wire….

 

-Gianna

Markjosephp
Community Specialist
Community Specialist

Hello Gianna,

 

I appreciate you keeping me in the loop. We can give these steps a whirl and see if the Nest Power Connector offer appears.

 

Try resetting at least one of your Nest Thermostat 2020 models. This will revert it back to its default settings and try adding it back again. During the process of choosing which wires you have, select the appropriate wires you have and see if the prompt detects that a Nest Power Connector would be needed as an offer.

 

Keep me posted.

 

Thanks,

Mark

Yes, both of my thermostats say they need a power connector. They keep going offline. This is very frustrating. Never had this issue with prior thermostats. Now I have to purchase 2 power connectors to solve this issue?

-Gianna

Markjosephp
Community Specialist
Community Specialist

Hi Gianna,

 

I'm sorry for the trouble this may have caused you. I totally understand that you've had previous thermostats that require no additional power. Unlike the other Nest Thermostats we have, the Nest Thermostat 2020 model often requires a C-wire to work, and a Nest Power Connector is an alternative for it.

Some zone relay panels don't provide enough power to smart thermostats, as they may require consistent power to function. Please let us know if you have any other questions or concerns.

 

Thanks,

Mark

aatienza
Community Specialist
Community Specialist

Hey there,

 

I just wanted to follow up to see if you still need our help. Please let us know as we would be happy to answer any questions you may have. 
 

I appreciate the help, Mark.

 

Thanks,

Archie

Thanks for following up. I still need to purchase 2 more power adapters since 2 of my thermostats don’t have C - wires and then I need to have them installed. This is becoming more costly than I ever expected not to mention my frustration every time the thermostats disconnect from wifi!

Gianna