Because of a Google software change, you may need to update your Google Nest thermostat’s connection to the Google Assistant before November 13, 2017 or you won’t be able to control your thermostat with Google Assistant on Google Home or your Android phone.
If you need to update, the Assistant on Google Home or your phone will give you friendly reminders when you use it to control your Nest thermostat. It will simply ask you to unlink and relink your devices.
Why you need to update
Unlinking and relinking your Nest thermostat to Google Assistant will ensure you’re able to to use features that are coming soon. If you don’t update, the connection will eventually stop working.
How to update your Google Assistant connection to Nest
Updating should only take a few minutes. You can use either use the Google Home app or the Google Assistant on your phone.
Follow the step-by-step instructions on Google's support page.
If you don’t see any devices that need updating
If you don’t see any devices with the word “update” next to them in the Google Home app or Google app, you can continue to control your thermostat and everything should work as expected.