Description
The Lennox 12U74 Defrost Heater Thermostat Sensor operates in heat pump and outdoor air conditioning systems to monitor evaporator coil temperature and manage defrost control during low ambient conditions. It detects surface temperature changes and communicates with the control system to initiate or terminate the defrost cycle when frost buildup affects heat transfer. It plays a key role in ensuring stable operation and protecting components in refrigeration and heating modes across residential and commercial applications. Installed on outdoor units, it supports consistent heat exchange and helps prevent ice formation that can restrict airflow and reduce system efficiency.









