Galaxy Top-mount refrigerator Parts — Browse All Models

Diagnosing thermistor problems in your Galaxy top-mount refrigerator

If the fresh food section of your refrigerator isn’t cooling properly, you could have a problem with the appliance’s thermistor or temperature sensor. The electronic control board monitors the thermistor and controls the refrigerator temperature based on thermistor signals. A broken thermistor could send the wrong information to the control board, resulting in a refrigerator temperature that’s too cold or not cold enough.

Follow the steps in this Sears PartsDirect video to check the thermistor to see if it’s working correctly. The video also shows how to check the wires that connect the thermistor to the electronic control board to make sure the problem isn’t with the wiring or the control board.

Common repair parts for Galaxy 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.