Aux (Auxiliary) Heat is available only for heat pump equipment that supports it. Aux Heat is heating that is generated by a secondary (i.e. auxiliary) heat source. The auxiliary heat source is generally less cost efficient than the heat pump. Therefore it is only used when necessary to reach a desired set point while in Heat mode. If you are in Aux Heat mode, your auxiliary heating source will be used as the primary source to heat the home.
You can switch to Aux Mode using the Mode button on the thermostat itself or the Sensi app, if your thermostat is configured properly.
If you think your thermostat is staging too often to auxiliary heat, check out our Boost feature. You may need to turn it off.
Learn more about Aux Heat Settings.