Nest thermostats can alert homeowners of potential heating or cooling problems - The Verge
Water Heater Not Heating? Thermostat Testing - YouTube
Lelit Bianca: Testing the High-limit Switches
Google Nest begins testing HVAC alerts, partners with Handy for booking service calls | TechCrunch
Elitech ECS-02CX Digital Temperature Controller Fahrenheit Thermostat – Elitech Technology, Inc.
Learning Thermostat problem. I am getting a T04 error and no heat when testing Heat or running heat, but testing Aux Heat works fine. Help please! *photos included* : r/Nest