Replacement For Part #WR09X10019. This part can be used on some Whirlpool brand refrigerators/freezers. 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. Dimensions 5.1 x 3.2 x 3.2".