Auxiliary heating intended solely for temporary use during the failure of the primary heating system is commonly termed “emergency heat.” This setting bypasses the heat pump’s usual operation, engaging electric resistance heating instead. An example scenario involves the complete failure of the outdoor compressor unit in a heat pump system during sub-freezing temperatures. The indoor unit will cease to provide heat through the standard heat pump cycle, necessitating the activation of this supplemental function to maintain a habitable indoor temperature.
The availability of this backup system prevents frozen pipes and potential property damage during periods of extreme cold when the primary heating source is unavailable. It offers a degree of security and comfort until the main heating system can be repaired or replaced. Historically, reliance on supplemental heating was more frequent due to the relative immaturity of heat pump technology. Modern heat pumps are more reliable, reducing the necessity for this function, but its presence remains a valuable safety net.