Nest Thermostat wiring issue with K connection on original thermostat.

[Backgarden97]

I have a new Nest Thermostat that is suppose to be compatible with my system according to the website compatibility check, however, the Google Home walk through says it isn't, because there is a K connection.  

Original thermostat was a programmable Honeywell TH8320UP1037.  There is a wire going to K.   The system is a basic conventional HVAC.

Advice please?

[Jenelyn_O]

Hi Backgarden97,

Thanks for posting in the Google Nest Community forum. I'm sorry for the delay. I'd love to know more about it. Could you please take a photo of the wires that are currently connected to your Nest Thermostat and to your HVAC control board?  

Best,

Jenelyn

[Backgarden97]

Hi Jenelyn, thanks for responding.   I have pictures of the thermostat and the "interface" between the thermostat and the HVAC .   Note that the K connection must be combining two lines from the HVAC.

[Jenelyn_O]

Hey Backgarden97,

Thanks for sharing the photo of your thermostat wiring. Nest Thermostats doesn't have a K terminal that's the reason why it turns out not compatible. I would suggest contacting a pro installer, as some of the proprietary systems can be rewired to be compatible. For additional reference, you can visit this link. 

Best,

Jenelyn

[Backgarden97]

OK, thanks anyway.

[zoeuvre]

Hi folks, 

As we got our resolution here, I'm going to mark this thread as complete. I'll be locking this thread if we won't hear back from you again in 24 hours. Should that happen, feel free to create a new one if you have more questions or have other concerns in the future. 

Thanks for your help, Jenelyn. 

All the best,

Zoe