Display shows dEF or Def; freezer may be in a forced defrost or reporting a defrost system issue.

Safety first: Unplug the freezer before removing the evaporator cover or working near the defrost heater. Components can be sharp and may still be hot after a defrost cycle.

• Step 1 – Allow cycle to complete: If the unit has just entered a defrost cycle, the dEF indication may be temporary. Wait 30–45 minutes to see if the code clears on its own.
• Step 2 – Check for heavy frost: Remove the interior rear panel to inspect the evaporator. If it is encased in solid ice, the defrost system is likely not working.
• Step 3 – Manual defrost (temporary fix): Unplug the freezer, remove food to a cooler, and allow the unit to thaw with the door open. Place towels to catch water. Do not chip ice with sharp tools.
• Step 4 – Inspect defrost components: Locate the defrost heater at the base or around the evaporator and the defrost thermostat clipped to the coil. Look for burned or broken heater elements and loose connectors.
• Step 5 – Restore power and monitor: After thawing, plug the freezer back in and monitor for 24–48 hours. If frost rapidly returns and the dEF indication reappears, the heater, thermostat, or control board likely needs replacement.

Testing the defrost heater and thermostat requires a multimeter and should be done by a qualified technician if you are not comfortable with electrical measurements.