Freezer displays F1 and does not reach the set temperature; compressor may run continuously.

Safety first: Unplug the freezer before accessing the control board or wiring.

• 1. Confirm symptom: Place a separate freezer thermometer inside to verify actual temperature versus display. If the display is wrong and F1 is shown, proceed.
• 2. Check sensors first: Test cabinet and evaporator NTC sensors as described for E1/E2. Replace any faulty sensors, as they directly affect thermostat operation.
• 3. Inspect control board: Access the main PCB and look for a compressor control relay. Check for signs of overheating or pitted contacts. A relay stuck closed can cause continuous running.
• 4. Reseat connectors: Ensure all sensor and compressor connectors are firmly seated on the PCB.
• 5. Replace control board if needed: If sensors are good and F1 persists, the thermostat logic or relay on the PCB is likely defective. Replace the main control board with the correct Severin part.
• 6. Verify operation: After replacement, allow 12–24 hours for temperatures to stabilize and confirm that F1 does not reappear.

Because thermostat faults can lead to food spoilage or over-freezing, monitor temperatures closely after any repair.