Display shows E9 and the refrigerator may not defrost properly, leading to ice build-up.

Safety: Unplug the appliance before working inside the freezer or on wiring.

Procedure:

• Manual defrost: Open doors, remove food, and allow all ice to melt from the evaporator and drain area. Place towels to catch water. Do not use sharp tools.
• Inspect defrost components: With the rear freezer panel removed, inspect the defrost heater, sensor, and wiring for damage or corrosion.
• Check defrost drain: Ensure the drain hole below the evaporator is clear. Flush with warm water and a small flexible brush if blocked.
• Test heater and sensor: Use a multimeter to verify heater resistance and sensor values. Replace any defective parts with genuine Neff components.
• Reassemble and monitor: After repairs, reassemble, restore power, and monitor for several days. If E9 returns, the main PCB defrost control may be faulty and should be assessed by a professional.