Freezer displays E3 and may not defrost properly, leading to ice buildup on the evaporator and reduced cooling.

Safety first: Disconnect mains power before accessing the evaporator or wiring. Avoid using sharp tools to remove ice.

• 1. Access evaporator area: Remove freezer drawers and the rear inner panel to expose the evaporator and defrost components.
• 2. Identify defrost sensor and fuse: On many SMEG freezers, the defrost sensor and/or thermal fuse is clipped to the evaporator tubing or attached to the wiring harness near the heater.
• 3. Inspect for damage: Look for burnt, cracked, or swollen components, and check for signs of overheating around the heater and wiring.
• 4. Test continuity: With the appliance unplugged, disconnect the defrost sensor/thermal fuse and check continuity with a multimeter. An open reading on a thermal fuse indicates it has blown and must be replaced; an NTC sensor should show a resistance value, not OL.
• 5. Replace faulty parts: Install the correct SMEG replacement sensor or thermal fuse. Do not bypass a blown thermal fuse; it is a safety device. Secure new components in the same position as the originals.
• 6. Check wiring harness: Inspect the harness from the evaporator area to the main PCB for pinched or broken wires and repair or replace as needed.
• 7. Reassemble and test: Refit panels, restore power, and monitor operation over 24 hours to ensure proper defrosting and that E3 does not return.

Warning: If the thermal fuse has blown, also verify that the defrost heater is not shorted or overheating; a technician may be required for full diagnosis.