Freezer display shows dH; defrost cycle may be extended or incomplete

Safety first: Unplug the freezer before accessing the evaporator or control board. Components can be hot immediately after defrost.

• Inspect evaporator area: Remove the rear interior panel and check for signs of overheating, such as melted plastic near the heater.
• Test defrost thermostat: When the evaporator is warm (above ~50°F/10°C), the defrost thermostat should be open (no continuity). If it remains closed, replace it.
• Check thermistor: Verify the evaporator thermistor resistance at known temperatures. Replace if readings are incorrect or unstable.
• Inspect wiring: Look for any signs of shorted wires around the heater and thermostat. Repair or replace damaged wiring.
• Control board: If all components test good, the main control board may be mismanaging defrost duration and should be replaced by a technician.