Manuel P Miami , FL February 08, 2019 Appliance: Samsung Refrigerator RFG237AARS/XAA-0000 Samsung Refrigerator Rfg237aars/Xaa-0000 / : Defrost error freezing evaporator faulty thermostat. How to replace Refrigerator Defrost Heater. Replaced defrost thermostat as well as heater coil. Also replaced the temp sensor to be safe. Do-It-Yourself Rating: Repair Time Estimate: 30-60 minutes