Heatcraft Refrigeration 4751C Defrost Thermostat 35-Open 55-Close

The Heatcraft Refrigeration 4751C Defrost Thermostat is a temperature-actuated control component used in commercial refrigeration systems to regulate evaporator defrost cycles. It operates by sensing coil temperature opening the circuit at approximately 35F, and closing at 55F to initiate or remove defrost operation. Installed on evaporator assemblies it ensures frost build-up is managed efficiently to maintain heat transfer performance, and airflow stability in HVAC systems. The thermostat supports stable system operation by coordinating timing within refrigeration and cooling equipment under varying load and ambient conditions.