Freezer shows E3; defrost cycles may not occur properly, leading to frost buildup on the evaporator and poor cooling.

Safety: Unplug the freezer before removing panels or working near the evaporator.

E3 typically indicates the defrost/evaporator sensor is not reading correctly.

• Access evaporator area: Empty the freezer enough to remove the rear interior panel. You may need to remove shelves and drawers.
• Inspect for heavy frost: If the evaporator is encased in ice, allow it to fully defrost (doors open, towels in place, or use a fan). Do not chip ice with sharp tools.
• Locate defrost sensor: Look for a small thermistor clipped to the evaporator tubing or attached near the top of the coil, often wrapped in foil or insulation.
• Check wiring and clip: Ensure the sensor is firmly clipped to the coil and the wires are intact. Re-seat any loose connectors.
• Test sensor: Disconnect the thermistor and measure resistance at known temperatures (e.g., in ice water). Replace if open, shorted, or far from LG spec.
• Reinstall panel: After replacing the sensor, reattach insulation and the rear panel to maintain proper airflow.

If the sensor is good but E3 remains, the main PCB or defrost control circuit may be faulty and should be evaluated by a professional.