The unit is 15 years old. Instead of just replacing the Adaptive Defrost Control Board , I opted to replace all parts related to include the Heating Element, Defrost Thermostat, and the Evaporator Fan Motor. I feel it was worth the extra money and piece of mind not to worry about what would fail next. In the long run it is was cheaper to replace those parts than replace all the food lost after it failed while we were on vacation! This company is just awesome! Great customer support and the standard shipping was delivered to my door in less than 24 hours of being placed!