What Is Auxiliary Heat?

Basically, auxiliary heat uses electric resistance heating to heat your home. Since electric resistance heating is much less efficient than your heat pump, you only want it to be on when necessary. ... To recap, auxiliary, or emergency heat should only be on when the outside temperature is below freezing.

Is it bad if auxiliary heat comes on?

Is AUX heat bad? The short answer is no. In fact, aux heat is a critical mechanism that keeps your heat pump properly running when the outdoor temperature drops. Since this type of unit doesn't work the same as a furnace, it can get cold.

Why is the auxiliary heat coming on?

What Does It Mean on My Thermostat? If your aux heat indicator is on, it means your heat pump needs a little help reaching its target temperature setting. Aux heat comes from the same heat source as emergency heat, but aux heat works together with your heat pump, so it's less expensive than emergency heat.