Thermostat displays aux heat - GE Zoneline AZ55H09D Air Conditioner

SOURCE: Thermostat show AUX HEAT

A heatpump has two sources of heat. One is when the heatpump is operating in normal heat mode, and the other is typically electric heat strips.

The strips come on when the unit is going into defrost, when the unit is not able to keep up with the demand for heat (really cold temps) and when the unit is not working properly.

Whne the strips are on, the T-stat displays "aux-heat" to indicate the strips are in operation.

If the strips are working properly you should have warmer air than with the HP alone. Try switchin it from "heat" to "emergency heat" and see what it will do.

When the HP is not able to keep up with the demand for heat then the heat strips come on, but they typically come on only when the room temp has gotten well below the thermostat setting.

In that situation it would be normal to see indoor temps at 63 degrees when the T-stat is set on 70.

But when you set it to E-heat it bypasses the heatpump operation and goes directly to the heat strips. If they are working properly it should maintain an accurate temp in the home.