Freezer only getting to 15F. Ice buildup in back of freezer

Here’s the most common causes that you can check out. There are three more causes but let’s see if one of these gets it first.

Cause 1

Defrost Control Board

The defrost control board determines how often to run the defrost cycle. If the board fails, the refrigerator will not go into the defrost cycle. Before replacing the defrost control board, first test the defrost heater and defrost thermostat. If the defrost heater and defrost thermostat are working properly, the defrost control board is likely defective.

Cause 2

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 evaporator coils. If the defrost timer is defective, it may not advance into the defrost cycle, or it may not send power to the defrost heater during the defrost cycle. To determine if the defrost timer is defective, slowly advance the dial into the defrost cycle. The compressor should turn off and the heater should turn on. If the timer does not send power to the defrost components or advance out of the defrost cycle within 30 minutes, this indicates that the defrost timer is not advancing. If the defrost timer is not advancing, replace it.

Cause 3

Defrost Heater Assembly

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