My Sub-Zero 532 refrigerator isn’t defrosting

Modern refrigerators has comfortable function - defrosting. You needn't think about how to defrost the freezer in the refrigerator - it’s all an automatic process. But what you must do, when the refrigerator stops defrosting? First of all, don’t panic. The problem could be solved easily. Problem is in defrost bi-methal thermostat. The defrost thermostat monitors the temperature of the evaporator coils. When the coils drop below a set temperature, the thermostat contacts close to allow power to flow to the defrost heater during the defrost cycle. In the defrost cycle, the defrost heater melts away any frost that may have accumulated on the evaporator coils. If the defrost thermostat is defective, the thermostat contacts will not close. As a result, the thermostat won’t provide power to the defrost heater. So today, we will replace bi-methal thermostat in refrigerator Sub-Zero 532 and similar models. 

1. Move your frozen food from the freezer to the refrigerator section and then unplug the power cord from the wall outlet.
2. Remove the spacer in the freezer shelf. Push the shelf to the left to release the right side of the shelf from the holes. Pull the shelf out of the freezer.
3. Remove the mounting screws from the evaporator cover. Pull the top of the evaporator cover down and unplug the evaporator fan wire harness. Push the evaporator cover to the left side of the freezer and disconnect the green ground wire and the ice maker wire harness from the evaporator cover. Pull the evaporator cover out of the freezer.
4. Unplug the wires from the defrost heater. Release the defrost bi-metal thermostat and the defrost thermistor from the evaporator coils. Unplug the freezer wire harness from the back wall and lay the freezer harness on a work table.
5. Cut the electrical wires close to the defrost  bi-metal thermostat. Remove the defrost bi-metal thermostat from the freezer wire harness.
6. Strip 1/4-inch of insulation from the ends of the supply wires and new defrost bi-metal thermostat wires. Slide the heat shrink tubes onto the new bi-metal thermostat wires. Connect the new bi-metal thermostat wires to the supply wires using the wire connectors. Slide the heat shrink tubes over the wire connectors. Heat the tubes using a heat gun to seal the connections. Tip: The defrost bi-metal kit includes the wire connectors and heat shrink tubes.
7. Plug the freezer wire harness into the back wall receptacle. Attach the defrost bi-metal thermostat and defrost thermistor to the evaporator. Connect the wires to the defrost heater.
8. Position the evaporator cover in the freezer compartment and reconnect the ice maker wire harness and ground wire. Push the evaporator cover to the center of the freezer compartment and reconnect the evaporator fan wire harness. Position the evaporator cover over the evaporator and reinstall the mounting screws.
9. Push the shelf into the mounting holes on the left side of the freezer compartment wall. Slide the shelf to the right and reinstall the shelf spacer.
10. Plug in the refrigerator to restore power.

Ready! Make some tests, your refrigerator must work like a new one! Feel difficulties with replacing? Give us a call and appoint a visit at a convenient time!