Installed two Nest Learning thermostats 6 months ago, and both have worked fine. About 12 hrs ago, the unit for the main part of our house went offline and displays a red flashing light. Screen is dark. Tried all the troubleshooting suggestions. Unit attempts to restart, but goes dark again after the “Restarting — Back in a bit” message. Unit briefly woke up and restarted on its own at about the 11 hour mark, the programmed temperature displayed along with the current room temp, but went dark again and nonfunctional after about 1 minute.
Swapped out the thermostat with the one in our master bedroom, and the HVAC unit came on immediately and is working fine. When the problem unit is reconnected to the master bedroom base, I get the same dark screen and flashing light. It appears to be a problem with the Nest unit and not the HVAC system or wiring.
Next steps?
