Thank you for the information. I am sorry to hear you are facing this behavior from your thermostat and would be happy to try and assist. The fastest way would be to get in touch over our direct support channels like phone, chat or social media but I would be happy to assist you.
It is good to hear you already checked the power and tried to power cycle. A few more details that need to be checked:
1. When was the thermostat installed?
2. When did you first notice this behavior?
3. Was it installed by a Nest Pro or by a heating/electrical engineer?
4. Did you notice any message on the thermostat display?
5. Did you notice any power cut in the area before this occurred?
6. Did you have any maintenance done on the heating or electrical system recently?
7. Do you have only one or multiple Google Nest thermostat devices at the location?
