Told to submit photo of current thermostat wiring to ensure compatability.

[Gregt7]

Looking into Google nest learning thermostat and the compatibility check told me to post a pic to ensure compatability  

 

[Houptee]

Red to RC, Orange to O/B, White to W1

then match up the rest to same.

[Gregt7]

My upstairs thermostat is the same, EXCEPT, the upstairs thermostat wiring does not have orange “O” wire. 

How would I wire this one and is it compatible with the Google nest learning thermostat?

[Houptee]

The Orange O/B is for heat pumps.

The upstairs must not be a heat pump system if no O wire.

So just put Red to Rc and then match up the other wires to the same terminals on the Nest.

[Gregt7]

I don’t believe I have a heat pump. Traditional furnace in the attic and air conditioner on the exterior of the house (live in TN if that’s helpful at all). 

does that change any of the wiring?

[Houptee]

That's strange why it has an O wire connected unless they just hooked it up only at the thermostat and it might not be connected on the furnace end to anything.

If you are sure it is not a heat pump you can leave the O wire disconnected.

Test that the system has heat and AC working normally.

[Markjosephp]

Hello folks,

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

Thanks for your help here, @Houptee.

@Gregt7, to be sure of your wiring configuration, could you please tell us the make and model of your HVAC system?

I'll look forward to your response.

Regards,

Mark

[Markjosephp]

Hi Gregt7,

I'm checking back in — how's it going? Still need our help with your systems compatibility with the Nest Thermostats? Let us know if you have more questions in mind.

Thanks,

Mark

[Markjosephp]

Hello Gregt7,

I'm checking in to make sure that you've seen our response. Please let us know if you have any additional questions or concerns before we lock this thread in 24 hours. 

Thanks,

Mark

[Jake]

Hey there,

I want to ensure you are good to go, and everything is working properly. Please let me know if you are still having trouble, as I will be locking the thread in 24 hours due to inactivity.

Best regards,
Jake

[adejaco]

I was told to submit my thermostat photo to check for compatibility with nest thermostat.

Here is the link:

https://photos.google.com/photo/AF1QipO4wjSnmTs1jpU3EyK7d7Sw1nsJXqdi6tfIUbgH

There are a lot of wires connected so before I purchase I really want to make sure this will work.  It currentky uses a carrier smart thermostat

[Markjosephp]

Hello adejaco,

I appreciate you taking the time to post your inquiry in this thread. Unfortunately, the Google Photos link you provided is not working. Could you please share with us another link or attach the photo to your reply so I can review it?

I'll look forward to your response.

Thanks,

Mark

[adejaco]

[Markjosephp]

Hey there,

Thanks for the photo. Could you confirm if you have HVAC accessories such as a humidifier or dehumidifier? Some thermostats have this (ACC+, ACC-) terminal to connect equipment like a whole-house humidifier or dehumidifier. If you have it, your HVAC system is Nest Learning Thermostat compatible, but we strongly recommend professional installation for these systems because incorrect setup, either due to miswiring or wrong software settings, can cause weird Heating, Ventilation, and Air Conditioning (HVAC) behavior and even damage the HVAC system.

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

Regards,

Mark

[adejaco]

yes, my current thermostat appears to have a demumidifer connected.  Will the basic Nest model work.  I can call my local HVAC guy if the wiring instructions are not clear

Will the 1st generation Nest Thermostat b2 compatible? 

[Markjosephp]

Hi adejaco,

Thanks for confirming that you have a dehumidifier. Based on your thermostat's wiring, you have second-stage cooling, with a wire connected to the Y2 terminal. With this, it's only compatible with the Nest Learning Thermostat.

Regards,

Mark

[Jenelyn_O]

Hi there,

Chiming in — I hope you get the answer you're looking for. Please let us know if you have further questions or concerns. 

I appreciate your help, Mark.

Best,

Jenelyn