My thermostat has gone completely blank, spoke to the man who installed it, said it sounds like it’s broken, is it still under warranty?
Does your Nest Thermostat Heat Link still work?Most of the time, the Heat Link is defective, and it stops charging the Nest Thermostat.
Please check if the Heat Link device still has some lights and try restarting the Heat Link to see if this helps. 🙂
Google Nest Help Center
Chromecast Help Center