Customer Questions and Answers for Defrost Control Board by Whirlpool

Hello Marie, You will want to look in the freezer compartment and remove the rear cover of the freezer. Check to see if the evaporator coil is impacted by frost. If it is then you will want to do a continuity check on the defrost heater and thermostat. If either does not have continuity then replace that part. If they both have continuity then you would need to replace the Defrost control board. If the coils are not impacted then you would want to check the return duct to make sure that it is not clogged with ice. This is located on the left wall of refrigerator section about midway down.