Refrigerator not cooling in fresh-food compartment but freezer is cold; back wall of freezer heavily frosted.

Safety first: Unplug the refrigerator before accessing the freezer evaporator. Water from melting ice can create slip hazards; use towels.

This classic symptom indicates that the freezer evaporator is icing over because the automatic defrost system is not working.

• Step 1 – Manual defrost: Turn off the appliance and leave doors open for 24 hours to melt all ice. Do not use sharp tools to chip ice.
• Step 2 – Access evaporator: Remove freezer drawers and the rear inner panel. Inspect the evaporator coil, heater, and defrost thermostat/sensor.
• Step 3 – Check components: Look for broken heater elements, loose connectors, or a thermostat that has come away from the coil. Test heater continuity and thermostat function with a multimeter if possible.
• Step 4 – Replace faulty parts: Install a new SMEG defrost heater or thermostat/sensor as required, ensuring good contact with the evaporator and secure wiring.
• Step 5 – Reassemble and monitor: After reassembly and power-up, monitor for several days. If frost returns quickly, the main PCB defrost control may be faulty and should be checked by a technician.