Evaporator Coils are Freezing.

Solution 1:

Defrost Heater Assembly

The defrost heater turns on several times throughout the day to melt away any frost that may have accumulated on the freezer evaporator coils. If the defrost heater does not turn on, frost will continue to accumulate on the evaporator coils, and the coils will eventually frost over. To determine if the defrost heater is at fault, use a multimeter to test the defrost heater for continuity. If the defrost heater does not have continuity, replace it.

Solution 2:

Defrost Thermostat

The defrost heater turns on several times throughout the day to melt away any frost that may have accumulated on the freezer evaporator coils. Before the defrost heater turns on, the defrost thermostat must sense that the evaporator coils are cold enough. If the coils are cold enough, the defrost thermostat will allow the defrost heater to turn on. (Usually, the temperature of the coils must be below 30 degrees Fahrenheit.) If the thermostat is defective, the defrost heater won’t turn on, causing the evaporator coils to frost over. To determine if the defrost thermostat is at fault, use a multimeter to test the thermostat for continuity. If the defrost thermostat does not have continuity, replace it.

Solution 3:

Defrost Timer

The defrost timer turns on the defrost heater several times throughout the day to melt any frost that may have accumulated on the freezer evaporator coils. If the defrost heater does not turn on, frost will continue to accumulate on the evaporator coils, and the coils will eventually frost over. In order for the defrost timer to turn on the defrost heater, the defrost timer must advance into the defrost cycle. If the defrost timer is not advancing properly, the defrost heater won’t turn on. To determine if the timer is defective, slowly turn the timer with a screwdriver or by hand. Turn the timer until it clicks. When the timer clicks, the compressor and fans will shut off. If the defrost thermostat and heater are working properly, the heater will turn on. If the heater turns on, this indicates that the timer is defective and must be replaced.

Solution 4:

Door Gasket

The door gasket prevents air from leaking into or out of the freezer. If the door gasket is torn or not creating a reliable seal, or if the freezer is not shut tightly, humid air can leak into the freezer. When this humid air passes over the cold evaporator coils, it condenses and freezes on the coils. If humid air is continually leaking into the freezer, the evaporator coils ice over too quickly, and the defrost cycle isn’t able to keep up. To determine if the gasket is creating a reliable seal, close the freezer door on a dollar bill and try to pull the dollar bill out of the freezer door. If the dollar bill sticks in place, the gasket is creating a good seal. If the dollar bill slides out or falls out, the gasket has a leak. Repeat this procedure all the way around the refrigerator door. If, at any point, the dollar bill does not stick, the gasket is defective. If the door gasket is defective, replace it.