A blinking red light will appear if the nests battery is too low to start. Youll need to check the power readings on your thermostat.

Nest Thermostat Is Not Working Properly Google Nest Community
Nest thermostat blinking red. Help with my nest issue. Your thermostat has a red blinking light a red blinking light means that the nests battery is running low. You can also speed up the process by disconnecting the thermostat display and plugging it into the usb port that came with your device. The nest should charge itself within a few hours but you can speed up this process by using a micro usb cable. It should turn back on automatically after the battery is charged. If the blinking red light doesnt go away or keeps coming back a persistent blinking red light can mean a couple of things.
Companies respond better when others are watching. The thermostats might turn off without your consent if you dont use it for some time but then it might turn on once it is accessed through the nest thermostat app. My nest thermostat is blinking red and its not powering on gethuman4776944s customer service issue with nest from may 2020. If youve successfully installed your nest thermostat but a blinking red light appears after youve been using it regularly for some time there may be a problem with the thermostat wiring or. Share to improve gethuman4776944s odds. This could be due to a wiring problem or extended power outage.
If you witness the red light blinking you should wait until the battery is 100 charged. When you have connected the nest thermostat to the system it should switch on.