Smart Thermostat Manuals & Owner Guides

What makes a smart thermostat ENERGY STAR certified

ENERGY STAR certifies smart thermostats as a product plus its connected service, using savings measured in real homes. Certified models must also meet limits on static temperature accuracy (±2.0 °F) and network standby power (3.0 W average), and each listing must describe how the product supports utility demand-response programs.

Compatibility and the C wire

• Most smart thermostats work with 24 V systems: gas, oil and electric furnaces, central air conditioners, heat pumps and many boilers.
• Line-voltage electric baseboard heaters need a thermostat designed specifically for line voltage.
• Many connected models require a common (C) wire for continuous power; some include an adapter for systems without one.
• Heat pumps, multi-stage and dual-fuel systems need correct installer settings — check compatibility before you buy.

Settings that save energy

Set back the temperature 7–10 °F for about 8 hours a day while you sleep or are away to save up to 10% a year on heating and cooling. Try about 68 °F in winter and 78 °F in summer when you are home, and use geofencing or occupancy sensing so setbacks happen automatically.

Smart Thermostat FAQ