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Will current wiring work with Nest Thermostat (W, RH, and RH/RC Jumper)?

vutopia
Community Member

Hi, I checked the Google Nest compatibility check which stated that a Nest Learning Thermostat might work in my current wiring configuration but I want to make sure with this community for confirmation.

The screenshots show the wiring to our current thermostat and a photo of the wiring to our furnace,  Will either of the Nest thermostats work with the current wiring?

Thanks!

Existing ThermostatExisting Thermostat  FurnaceFurnace

1 Recommended Answer

CoolingWizard
Platinum Product Expert
Platinum Product Expert

Yes indeed.  Your thermostat controls a heating system only.  There is no Common wire at the thermostat although it is present in the furnace.  

Ken, The AC Cooling Wizard

NestPro, Google Pro, Mechanical Engineer and HVAC service company owner.
If my answer solved your problem, click Recommend this Answer below, and If it helped you, please give a Kudo.

View Recommended Answer in original post

12 REPLIES 12

CoolingWizard
Platinum Product Expert
Platinum Product Expert

Yes indeed.  Your thermostat controls a heating system only.  There is no Common wire at the thermostat although it is present in the furnace.  

Ken, The AC Cooling Wizard

NestPro, Google Pro, Mechanical Engineer and HVAC service company owner.
If my answer solved your problem, click Recommend this Answer below, and If it helped you, please give a Kudo.

Hey folks, 

We appreciate your help here, @CoolingWizard.
@vutopia, I wanted to follow up and see if you are still in need of any help. Please let me know if you are still having any concerns or questions from here, as I would be happy to take a closer look and assist you further.

Thanks,
Mel

Hi…actually, I did have another question. Do I need the Nest Power Connector for my config for either Nest thermostat? Thanks!

Markjosephp
Community Specialist
Community Specialist

Hi vutopia,

 

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

 

Most of the time, Google Nest thermostats can use the heating and cooling connections to charge their internal battery. To reliably supply power to your thermostat, you might need to attach the Nest Power Connector in some circumstances. Here are some references to help you install your new Nest Power Connector on your HVAC system.

 

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

 

Best regards,

Mark

Hi folks,

Chiming in to see if you still need assistance with this. Let us know if you have additional questions ― we'd love to help.

Best,
Mel

Hi everyone,

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

akwarmguy
Community Member

I just installed my Nest Learning Thermostat last night and the picture I took of the control before installing it looks just like yours did. It has a W and an Rc and Rh that are jumpered together. Everybody says it should work, and when I installed it, the system fired up and started shooting warm air. Threw the original thermostat in the garbage and went to sleep. By morning it was cold. Took everything apart and reinstalled from scratch. No errors. Ran test, again, heat comes on, runs for several minutes, then turns off. No errors. Power cycle it. It runs a few minutes. Shuts off. It was 60 in the house and with temperature dropping (it's 8 degrees outside) I had to fish the old thermostat out of the trash and put it back on so the pets don't freeze. I will try the installation again once I get the Nest Power Connected I ordered installed. I hope you have better luck with your new thermostat than I did.

Markjosephp
Community Specialist
Community Specialist

Hello akwarmguy,

I'm sorry to hear about the experience you had after installing your Nest Thermostat. I'd love to help — lets see what's going on.

If your system can’t deliver consistent power to your thermostat to keep its battery charged or correctly control heating, you may experience odd heating behavior. Installing a C wire or the Nest Power Connector would help, and here are some references to help you install your new Nest Power Connector on your HVAC system:

Please let us know if you have more questions.

Best regards,

Mark

I had ordered the Nest Power Connector as I was putting the original thermostat back in place but I noticed a disconnected blue/green wire in the wall on the thermostat side and found the same wire floating in the control panel on my furnace which was not attached to anything. It seems like the installer didn't bother connecting the C on the furnace side since it wasn't necessary with the prior setup.

I was comfortable with the very basic wiring, so I followed another guide I found online about how to connect a floating C wire to the furnace and then put the Nest back in and fired it up. Happy to say everything is working properly now that I have a C wire. I can't say whether the Nest Power Connector would have solved this or not since I ended up cancelling the order, but I can certainly say that in this particular setup like the OP posted a picture of, my system definitely needed a C to work properly.

Markjosephp
Community Specialist
Community Specialist

Hi there,

Sounds great! @akwarmguy, thanks for updating us on your efforts to address your concern by finding a fix for installing a C wire. I'm glad to hear that it's working as expected. Please let us know if you have any other questions or concerns.

Best,

Mark

Hi folks,

Chiming in to see if you still need assistance with this. Let us know if you have additional questions ― we'd love to help.

Best,
Mel

EdwardT
Community Specialist
Community Specialist

Hi folks,

 

I'm 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