HVAC ANSWERS · EQUIPMENT AND EFFICIENCY
Auxiliary and emergency heat
Canonical HVACentric knowledge for residential questions on this topic.
DIRECT ANSWER
Auxiliary heat is supplemental heat that controls may use when the heat pump alone cannot meet the current demand or during certain operating conditions. Emergency heat is typically a manual mode that bypasses normal heat-pump heating. Occasional auxiliary operation can be normal; frequent or unexplained operation should be evaluated with thermostat setup, outdoor conditions, equipment performance, controls, and the building load in mind.
Questions this topic covers
These are examples of natural wording that map to this maintained topic. They are not separate pages or duplicate answers.
- Why is AUX heat showing on my thermostat?
- What is emergency heat?
- Should auxiliary heat run with a heat pump?
- Why are the heat strips coming on?
- Is backup heat expensive to operate?
Sources used for this answer
HVACentric uses public primary and authoritative sources as research anchors. Property-specific decisions still require direct verification.