Google nest blowing hot air when in cool mode

[SCDSCHR]

I have two Nest Learning thermostats.  One is called "Down"; the other is called "Up".  "Down" has worked perfectly for years until yesterday when we decided to run the AC.  After a few minutes, the thermostat caused warm air to blow.  I swapped the two thermostats replacing "Down" with "Up". ("Up" thermostat works fine.)  Connecting the "Up" thermostat to the downstairs unit solved the problem.  Connecting the "Down" thermostat to the upstairs unit, caused heat to blow when the thermostat called for cool.  What is your take on the problem?  Thank you!

[DeboraJ]

Hi @SCDSCHR

Thank you for reaching out to the community! I'm sorry to hear you're experiencing inconveniences with your thermostat, which you've named “down,” due to unexpected hot air blowing. Let me assist you with this.

Before we proceed, I need some relevant information to provide you with the most effective troubleshooting steps:

• Could you please send us a photo of the thermostat wiring you're having trouble with?
• Besides relocating the thermostat, have you tried any other measures to resolve this?
• What is the make and model of your heating, ventilation, and air conditioning (HVAC) equipment?
• Are all the wires securely connected to their terminals, with no loose or exposed wires?

I'll be happy to assist you further once you provide this information.

Best regards,

Debora

[SCDSCHR]

Thanks, Deborah!  I did the troubleshooting and determined the Nest thermostat was bad.  I replaced it and everything is fine now.  🙂

[DeboraJ]

Hi @SCDSCHR

I'm happy to hear that you received a replacement to resolve the inconvenience with your thermostat! I hope things go better for you now. Please remember that you can always reach out to us for any further issues.

Best regards,

Debora