Quick answer
HouseIt uses this topic to decide which input changes the recommendation. The purpose is to move from a generic search phrase to a home-specific decision without pretending an online screen can replace measurements or an on-site diagnosis.
What AUX heat usually means
The thermostat mode describes what the controls are asking the system to do; it does not by itself identify a failed component. Outdoor conditions, duration, comfort and whether the mode was manually selected are the useful context.
AUX heat versus Emergency Heat
The thermostat mode describes what the controls are asking the system to do; it does not by itself identify a failed component. Outdoor conditions, duration, comfort and whether the mode was manually selected are the useful context.
When backup heat becomes a clue
HouseIt uses this topic to decide which input changes the recommendation. The purpose is to move from a generic search phrase to a home-specific decision without pretending an online screen can replace measurements or an on-site diagnosis.
Safe checks before calling
HouseIt uses this topic to decide which input changes the recommendation. The purpose is to move from a generic search phrase to a home-specific decision without pretending an online screen can replace measurements or an on-site diagnosis.
How HouseIt reaches this result
HouseIt evaluates the combination of answers rather than turning one age, thermostat label or rule of thumb into a definitive diagnosis. The result is a screening recommendation and can show where professional verification is still needed.
What this tool cannot verify remotely
Do not instruct users to open electrical compartments, bypass heat strips, or service refrigerant circuits. HouseIt cannot inspect concealed conditions, measure combustion/electrical/refrigerant performance or replace a licensed on-site diagnosis.