Freezer displays E3; defrost cycles may not occur properly, leading to frost buildup on evaporator.

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

• Access the evaporator: Remove shelves and the rear interior panel to expose the evaporator coil.
• Locate the defrost sensor: The defrost thermistor is typically clipped to the evaporator tubing or attached near the top of the coil with a plastic clip.
• Inspect placement: Ensure the sensor is firmly clipped to the coil. If it is hanging loose, reattach it; a loose sensor can cause incorrect readings and E3 errors.
• Check wiring: Look for brittle insulation, corrosion, or ice damage on the sensor leads. Gently thaw any ice with a hair dryer on low, keeping it moving and away from plastic parts.
• Test the sensor: Disconnect the thermistor and measure resistance at freezer temperature. Compare to expected NTC values. If resistance is far out of range, replace the sensor.
• Replace if needed: Install a new defrost/evaporator thermistor, routing wires along the original path and securing with clips or zip ties.

If the sensor and wiring are good but E3 remains, the main control board's defrost circuit may be faulty and should be checked by a professional.