A thermostat that short-cycles, ignores its schedule, or loses its connection can leave a whole house too hot or too cold. Start here for thermostat problems and settings, help choosing a thermostat, and thermostat installation steps you can plan before you pull the old unit off the wall. The section also covers smart locks, doorbells and security devices that connect to the same home setup. Choose the device you are dealing with and follow the guide that fits its symptoms.