Kenmore Refrigerator Error Code F dH

The F dH error code on a Kenmore refrigerator indicates a freezer defrost failure. Specifically, the control board triggers this fault when 80 minutes have elapsed since the defrost cycle began and the defrost sensor has still not detected a temperature above 40°F (5°C). Under normal operation, the defrost heater melts frost accumulation on the evaporator coils, and the defrost sensor monitors the temperature rise to confirm the cycle is working. When that temperature threshold is never reached within the allotted time, the board logs F dH and typically terminates or skips the defrost cycle.

Four primary causes are associated with this code. A blown thermal fuse (temperature fuse) in the defrost circuit will cut power to the heater entirely, preventing any heat from reaching the evaporator. A failed or open-circuit defrost heater itself produces the same result. A jammed or frozen drain can trap water and ice at the base of the evaporator, insulating the components and preventing the temperature sensor from registering the expected rise. Finally, a faulty relay responsible for switching power to the defrost heater can fail to close, leaving the heater unpowered despite the control board issuing the defrost command.

Diagnosing this fault requires testing each component in the defrost circuit. The temperature fuse can be checked for continuity with a multimeter; a reading of no continuity confirms it has blown. The heater element should also be tested for continuity and proper resistance. The drain should be inspected for ice blockage. The heater relay, typically located on the control board or a separate relay board, should be evaluated for proper switching operation. Addressing this fault promptly is important because a non-functional defrost cycle will allow frost to accumulate on the evaporator, eventually restricting airflow and causing the refrigerator to lose cooling capacity.