Auxiliary heat on your thermostat is a secondary heating function that your thermostat automatically switches to when its too cold outside for your heat pump to extract warmth from the air. This type of heating is often triggered when the outdoor temperature drops to near or below-freezing temperatures. Auxiliary heat will also turn on when your heat pump goes into defrost mode to prevent blowing cold air into your home while the outdoor condenser is thawing.

When the temperature inside your home drops below the goal temperature you’ve set the thermostat to, your thermostat energizes auxiliary heat. This commonly takes place once the indoor temperature on your thermostat reaches 2-3 degrees colder than the set indoor climate temperature. Auxiliary heat will turn off once your home reaches the thermostat set point.

Auxiliary heat is a backup heating system within your heat pump, otherwise known as electric resistance heating. It is a secondary heat source (either gas or electric) that has been deployed to help your heat pump reach a warm enough temperature when the weather outside is extremely cold. Unlike emergency heat settings which are run if your heat pump breaks, aux heat only kicks in when your heat pump can’t reach targeted settings.

Your auxiliary heat turns on when your heat pump needs assistance reaching your set indoor temperature. The heat pump will automatically energize its auxiliary heat strip to help warm your home. Your thermostat plays a big part in determining when auxiliary heat is activated. When the temperature inside your home drops three or more degrees below your set limit, your thermostat will kickstart the auxiliary heat.

In summary, auxiliary heat is a secondary heating function that your thermostat automatically switches to when its too cold outside for your heat pump to extract warmth from the air. It is a backup heating system within your heat pump, otherwise known as electric resistance heating. When the temperature inside your home drops below the goal temperature you’ve set the thermostat to, your thermostat energizes auxiliary heat. This commonly takes place once the indoor temperature on your thermostat reaches 2-3 degrees colder than the...