Definition
Emergency heat is a manually selected thermostat setting on heat pump systems that shuts off the outdoor heat pump and heats the home with backup heat only, usually electric resistance strips or, in dual-fuel systems, a gas furnace. Unlike auxiliary heat, which engages automatically, emergency heat is meant for a failed or damaged heat pump.
Also called: EM heat
Why it matters to you.
If an outdoor unit is damaged by a falling limb or encased in ice during a Kentucky winter storm, EM heat can keep the house warm until it is repaired. On an all-electric system it runs entirely on resistance heat, so leaving it on for weeks uses far more electricity than normal operation.
Practical guidance.
Switch to EM heat only when the outdoor unit is clearly not working or physically damaged, then schedule a repair rather than living on it. Diagnosing why the heat pump failed, including electrical and refrigerant checks, is licensed-technician work.
About this definition
Written by the Feistritzer Heating & Air Conditioning team — family owned and operated in Danville since 1976, Kentucky HVAC license M02584. Definitions inform; a whole-system diagnosis in your home decides.