Geothermal Primary (choice greyed out)

[odosou]

Recently installed a Nest 4th gen learning thermostat, on my Bryant Geothermal, with resistive heat aux. Have set it up and even a factory reset. Selected single heat forced air, but under primary heat in Google app it consistently shows electric and is greyed out not allowing me to change to geothermal option. Using Y1, G, OB, W2/Aux, C and Rh wires confirmed on a CXM controller? Any thoughts?

[Rusell]

Hi Odosou,

Thanks for posting in the Google Nest Community. I understand you're experiencing an inconvenience with the installation of your 4th gen Nest Learning Thermostat on your Bryant Geothermal system. the primary heat source in the Google Home app consistently shows 'electric' and is greyed out, therefore this doesn't let you select the geothermal option. I appreciate the troubleshooting steps you've done so far. Help is here!

Besides, I'd like to tell you that your  Bryant Geothermal system is not compatible with the Nest Learning Thermostat 4th gen but this is only available for the  following Nest thermostat: Nest Learning Thermostat (2nd gen), Nest Thermostat E and Nest Learning Thermostat (3rd gen). 

This is compatible with the following Nest Thermostats: Nest Learning Thermostat (2nd gen), Nest Learning Thermostat (3rd gen) and Nest Thermostat E.

Also, please take a look at this article to get more information regarding your concern: Nest thermostat compatibility.

If you have any further questions, please don’t hesitate to reply to this post. I'll be happy to assist you further!

Best regards,

Rusell.