Emergency heat is when you use your supplemental heat (2nd stage) by itself, without the use of your heat pump (1st stage heat). This option is not available for non-heat pump systems.
Auxiliary heat (only on heat pump systems) is when the 1st stage heating equipment cannot keep up with the space heating demand and a 2nd stage call for additional heat is required. With an Air Handler with electrical heat, when 2nd stage runs it will run in conjunction with 1st stage. With dual fuel systems, when 2nd stage runs, it will turn off 1st stage heating and run only on 2nd stage.
If your AUX lockout temp is 40°F/4.4°C, then auxiliary heat will come on when the outdoor air temperature drops below 40°F/4.4°C. With Heat Pump Balance, you don't have to worry about the AUX lockout temperature.
For more information or a visual representation of steps please reference our user guide here
