Sub-Zero Top-mount refrigerator Parts — Browse All Models

Common repair parts for Sub-Zero top-mount refrigerators

• Compressor. The compressor is a positive displacement pump rotated by an electric motor. The compressor receives low-pressure refrigerant gas from the evaporator and rotates to compress that refrigerant to a high-pressure gas that moves through the condenser. The refrigerant gets hot when compressed by the compressor pump. The condenser is a heat exchanger that removes heat from the refrigerant gas and condenses it into a high-pressure liquid refrigerant. The high-pressure liquid refrigerant flows through the expansion device and into the evaporator that's at low pressure. The high-pressure refrigerant expands and evaporates. It absorbs the latent heat of vaporization as it changes from a liquid to a gas, which causes the cooling action in the evaporator. The refrigerant flows through the evaporator and back to the compressor where the cycles starts over.
• Compressor start relay. The compressor start relay starts the compressor and shuts off the compressor if the motor overheats. Replace the start relay if it's defective.
• Condenser fan. The condenser fan is in the machine compartment of your refrigerator next to the compressor. It moves air across the condenser coils to help cool the hot refrigerant coming out of the compressor. The refrigerant is cooled before it moves through the expansion device and into the evaporator.
• Defrost heater. The refrigerator defrost heater melts frost from the freezer’s evaporator fins. Replace the defrost heater if it doesn't heat when activated.
• Defrost timer. The defrost timer is an electro-mechanical timer that controls the intervals between automatic defrost cycles in your refrigerator. The defrost timer motor runs and moves the components in the device. When the contacts for the defrost cycle are engaged, the compressor stops and the defrost heater turns on briefly to melt frost from the evaporator fins. Removing the frost promotes a more efficient exchange of heat across that component. When the fins are defrosted, the contacts disengage, allowing normal cooling in the refrigerator.

Troubleshooting your Sub-Zero top-mount refrigerator when its freezer isn't cold enough

Defrost system problems, dirty condenser coils, fan failures, leaky door gaskets or control problems can lead to your freezer not getting cold enough.

If your freezer is too warm to keep the ice cream firmly frozen and you see lots of frost inside the entire freezer compartment, then warm, moist air may be leaking through the refrigerator or freezer door gaskets. Check all door gaskets for damage and replace any damaged door gaskets.

If the gaskets are in good shape but a door sags on its hinges and creates gaps between the door gasket and the cabinet around the door openings, adjust the refrigerator door hinges so the gaskets seal properly to the cabinet around the door openings.

If you see frost buildup only on the back freezer compartment wall, then the automatic defrost system may have failed. When working properly, the defrost system melts frost off the evaporator coils every 8 hours or so to keep the air paths through the evaporator clear so the freezer and refrigerator compartments cool properly. If the automatic defrost system breaks, frost builds up on the evaporator and back freezer compartment wall. The frost buildup blocks cooling air paths through the evaporator so the freezer doesn't cool well. Our video troubleshooting defrost system problems in refrigerators will help you diagnose and repair the defrost system in a common top-freezer refrigerator. You can also use the basic steps in the video to troubleshoot defrost system problems in side-by-sides and bottom-freezer refrigerators. If the defrost system in your refrigerator isn't working, you may need to replace the defrost sensor, defrost heater or other defrost components depending on the type of defrost system that your refrigerator uses.