The Defrost Thermostat is an OEM replacement part for GE refrigerators. It is a temperature-sensing device located near the refrigerator coil that triggers automatic defrost cycles. The defrost thermostat monitors frost buildup and energizes a heating element to safely melt accumulated ice. Causes of a bad defrost thermostat can include exposure to freezing interior temperatures over time, or damage from impacts that compromise the thermostat's calibration. Without proper function, frost risks impeding efficient heat transfer. Symptoms include: Excessive ice buildup inside refrigerator compartments The inability of the refrigerator to maintain a frost-free operation Higher energy bills due to continuous compressor runtime to fight buildup This OEM replacement part is compatible with Hotpoint, RCA, and some Kenmore designs.WR50X29776 (AP6783321) replaces WR50X10088, 4864448, PS12583189, WR50X10036.