#Shorts Many top freezer refrigerators use a defrost timer. This mechanical timer switches between the cooling circuit and the defrost circuit. After 8 hours of runtime power is switched to the defrost circuit. This runs for about 30 minutes before power is returned to the compressor and fans.
Not all refrigerators have defrost timers. Some have an dedicated defrost control board and in newer models the main control board will handle all of these functions.
Understanding how the defrost timer works can help you troubleshoot your refrigerator. If the refrigerator isn't cooling properly then it could be an issue with the defrost timer. You can use a multimeter to test the defrost timer for continuity. This can help you determine if it is working properly.
