How To Fix A Refrigerator and Freezer That's Too Warm

The cold control is a temperature controlled switch that supplies power to the compressor and fan circuits in the refrigerator. If the compressor and fans are operating normally but not running often enough or long enough to maintain the correct temperatures in the fresh food and freezer sections, then the cold control may be defective or out of calibration. Normal fresh food temperatures are in the 38° Fahrenheit range with the control set to mid point. Verify that the capillary tube or sensing bulb is not damaged or out of position and that the wire terminals are not loose or corroded. You can check the continuity of the control with a multi-meter. Remove power from the appliance to perform this inspection.

The evaporator fan motor is located in the freezer compartment behind the evaporator cover and is used to circulate the cold air throughout the refrigerator when the compressor is running. If the fan is defective then temperatures in the freezer section will rise slowly and temperatures in the fresh food section will rise more rapidly and the compressor will run longer and more frequently than normal. With the compressor running you should also hear the evaporator fan running at the same time, as well as the condenser fan which is located next to the compressor.

If the evaporator fan is not operating, remove power from the appliance and then remove the evaporator fan cover. Check to see if the fan blade is attached securely and that the motor will turn freely. If the motor and fan appear normal, then you should verify that power is being supplied to the motor when the compressor is running. This is a live voltage check and should only be performed by a qualified person. If power is present then you should suspect that the motor is defective. You can check the motor for continuity with a multi-meter.

Some newer models of refrigerators may use an electronic control board. Thermistors or temperature sensors are connected to the control board and are used to monitor temperatures in the fresh food and freezer compartments. The control board uses this information to control the operation of the compressor, fan motors and defrost system. If the temperatures are too warm then the electronic control could be at fault. Electronic controls are complex and expensive and usually reliable, so you should first verify that all of the other components such as the compressor, fans and sensors are operating properly before condemning the control. Some manufacturers may provide specific information that will help in diagnosing a defective control.

In models that use an Electronic Control, a thermistor or temperature sensor may be used to monitor fresh food and freezer temperatures. The sensor is a small capsule like device that is protected by a plastic shield and will vary in resistance depending on the temperature. The control board uses this information to turn on the compressor and fan circuits as well as to operate the damper control on some models. If a sensor becomes damaged or defective it may incorrectly signal the control board to turn off the compressor and fans and result in warmer than normal fresh food and freezer temperatures. Individual manufacturers may have specific information available to test these sensors, depending on the model involved, and may also provide a fault code on the electronic control board on some models.

The defrost timer is an electro-mechanical timer that operates a set of contacts that control both the compressor circuit as well as the defrost heater circuit. Most timers will activate a defrost cycle every 8-10 hours of compressor run time. This normally occurs about once every day or two. The defrost timer will normally terminate the defrost cycle after 20 to 30 minutes and the compressor and fans will start again. The defrost timer can usually be found near the bottom of the refrigerator behind the kick plate, in the control panel in the fresh food section, or in the back of some side-by-side units. The wiring diagram for the refrigerator will indicate the correct terminals on the timer to check for switch or motor continuity, and will also identify the harness leads to the heater. Power should be removed to perform these tests and live voltage checks should only be performed by qualified persons.

The defrost thermostat is a safety thermostat in series with the defrost heater and is used to terminate the defrost cycle when the evaporator reaches a specific temperature, usually rated at 38° to 47° Fahrenheit. The thermostat is normally mounted on the tubing of the evaporator and will be a closed circuit for temperatures below 15° Fahrenheit. If the thermostat is defective and remains open circuit, then the defrost heater will not be energized and no defrost will take place. You can check the thermostat for continuity with a multi-meter if you are satisfied that the temperature is below 15°Fahrenheit. Remove power from the appliance before performing this test.

The defrost heater is the device that actually melts the ice and frost from the evaporator coils. It is normally located beneath the evaporator coils, and is typically a wire filament contained in a glass or aluminum tube. There may be more than one heater depending on the shape of the evaporator. To access the heater or heaters, you will need to remove the evaporator cover. Disconnect power from the appliance before attempting this repair. The heater can then be tested with a multi-meter for continuity.

Most modern frost-free refrigerators will have a fan cooled condenser coil. This normally located near the compressor at the bottom rear of the refrigerator. The condenser fan circulates air through the condenser coil to remove heat. If the refrigerator is warmer than normal and the compressor is running almost continuously, then you may have a problem with the condenser fan motor. The condenser fan motor runs at the same time as the evaporator motor and the compressor. If the fan motor is not turning at all the condenser will not be able to expel the excess heat and the compressor will run almost continuously.

To inspect the fan, first disconnect the power and then remove the rear access panel. Look for any debris or an obstruction that might be preventing the fan from moving freely. This area needs to be kept free of obstructions so that air can move freely and should be vacuumed on a regular basis. Verify that the fan will turn freely. If the motor is seized it will need to be replaced. If the motor turns freely then disconnect power to the appliance and remove the wires to the fan motor. You can now check the motor for continuity with a multi-meter.