First check which model of thermostat you have:
How to tell which Nest thermostat you have - Google Nest Help
If you have Nest Thermostat (2020) or Nest Learning Thermostat (4th gen), can you confirm you're using the Google Home app? Also check you're looking at the right home by tapping the name of your home at the top left where you can switch between homes.
If you have Nest Thermostat E or Nest Learning Thermostat (1st, 2nd, 3rd gen), can you confirm you're using the Nest app? Also check you're looking at the right home by tapping the menu dropdown at the top left where you can switch between homes?
If you've checked all those things, and you're using the same account you set it up with, follow the steps below to reset and add it back to your app.
Nest Thermostat (2020), Nest Learning Thermostat (4th gen)
- On the thermostat, go to Settings > Account > Disconnect.
- Follow the setup steps: Get started with your Nest Thermostat - Google Nest Help
Setup these models using the Google Home app. The QR code and setup key are physically printed on the back of the thermostat for Nest Thermostat (2020) and will be displayed on screen for Nest Learning Thermostat (4th gen).
Nest Thermostat E, Nest Learning Thermostat (1st, 2nd, 3rd gen)
- On the thermostat, go to Settings > Reset > Account connection. If you don't see this option, you'll need to select All settings.
- Follow the setup steps: Add your Nest thermostat to the Nest app - Google Nest Help
Setup these models using the Nest app. The QR code and setup key are in the settings on the thermostat itself and are not printed on the device.
