H1 or HI displayed; high temperature alarm active; food starting to thaw.

Safety: No internal electrical work is required for basic checks; unplug only if removing panels.

• Check door seal: Inspect the door gasket for gaps, tears, or debris. Clean with warm soapy water and ensure the door closes fully.
• Reduce warm loading: Avoid placing large quantities of unfrozen food at once. Spread items to allow airflow.
• Verify temperature setting: Ensure the setpoint is around -18°C. Adjust if necessary.
• Listen for compressor and fan: Confirm the compressor and internal fan (if fitted) are running. If silent for long periods, there may be a control or compressor issue.
• Allow recovery time: After correcting door or loading issues, allow 12–24 hours for temperature to recover. The alarm may clear automatically.
• Further diagnosis: If the freezer cannot reach temperature, investigate sensors, condenser cleanliness, and sealed system as described in other entries.