Wiring Compatibility

[Vwilson23]

  

Good morning, as instructed I am just looking to see if my existing wiring is compatible with the Google Nest thermostat Model GA02082-US.

Any help is appreciated, thank you. 

[sporfrog]

It's unusual to see a two wire thermostat with terminals labeled R and C.  Do you know any details about your HVAC system?  Is it a very basic heat only system or something more complicated?  Do you know the model of the existing/old thermostat?

[Vwilson23]

I see Lennox Model CX34–25A-6F- 1.

Serial # 6016E46127

thermostat - Honeywell 

model # THX9421R5021WW

Should be basic heat system was updated 2017

[sporfrog]

I am not sure, but it appears the thermostat is using a proprietary wiring system - at least at that location.  The thermostat supports RedLINK, which further implies some level or proprietary system.  Sometimes a thermostat is more of a satellite controller, often if a home has multiple thermostats, for a larger central system thermostat controller located elsewhere.   My guess is that you could not install a Nest thermostat using that cable and those wires in the picture.

[zoeuvre]

Hi Vwilson23,

I wanted to check if you managed to see sporfrog's post. Please let me know if you have any questions from here. I would be happy to assist, and make sure you are good to go.

Thanks, 

Zoe

[zoeuvre]

Hi there, 

We haven’t heard from you so I'll go ahead and lock this thread in 24 hours. If you run into any more issues in the future, please feel free to create a new thread.

Regards, 

Zoe