Why does my refrigerator not go into defrost mode?

There are 3 common issues as to why you may be experiencing a defrosting issue with your freezer. A faulty defrost timer, a defective defrost heater and a defective thermostat. Any frost-free refrigerator has a defrost system that controls the cooling and defrost cycle.

 

To test the timer, manually turn the dial into the defrost position. This should shut off the compressor and turn on the heater. If after 30 minutes the timer does not complete the defrost cycle or power the defrost components, it is not advancing properly. A non-advancing defrost timer should be replaced.

 

Set it to the Ohms setting and touch the probes to the thermostat’s terminals. If the multimeter reads zero, the thermostat is functioning correctly. If it reads infinity, it's time for a replacement.