Freezer section shows E4 and heavy frost builds up on the freezer evaporator; airflow to upper drawers is reduced.

Safety first: Unplug the refrigerator and wear cut-resistant gloves when working near metal fins.

Steps:

• 1. Defrost the freezer: Remove food, drawers, and the rear panel. Melt ice with bowls of hot water or a hair dryer on low, keeping electrical parts dry.
• 2. Locate the evaporator NTC: It is typically clipped to the evaporator tubing or embedded in a plastic holder on the coil.
• 3. Inspect the sensor: Ensure it is firmly attached to the coil and not dangling. Check for cracked housing or damaged cable.
• 4. Measure resistance: Disconnect the sensor and test with a multimeter. Compare to expected NTC values at the measured temperature. Replace if readings are abnormal.
• 5. Check wiring continuity: Verify continuity from the sensor connector to the main PCB. Repair any breaks or corroded connectors.
• 6. Replace the sensor if needed: Clip the new NTC in the same location and route the cable along the original path, securing it away from the defrost heater.
• 7. Reassemble and monitor: Refit the rear panel and drawers, restore power, and monitor for normal frost pattern and absence of E4 over the next 24–48 hours.