Display shows d1 or door symbol; audible alarm sounds; unit may stop cooling after prolonged door open.

Safety first: No internal electrical work is required for basic checks, but unplug the unit if adjusting hinges or removing covers.

Steps:

• 1. Check for obstructions: Ensure shelves, bottles, or racks are not preventing the door from closing fully.
• 2. Inspect door gasket: Look for gaps, tears, or hardened sections of the gasket. Close the door on a sheet of paper at several points; if it pulls out easily, the seal is weak.
• 3. Verify door alignment: Check that the door is level and square with the cabinet. Adjust hinges according to the Liebherr installation instructions if the door is sagging.
• 4. Test door switch: On many models, a magnetic reed switch is hidden in the cabinet frame. Use a small magnet to pass near the switch area with the door open; if the alarm stops and light goes off, the switch is working.
• 5. Replace faulty parts: If the switch does not respond, have the door switch or reed sensor replaced. If the gasket is damaged, install a new Liebherr door gasket, warming it slightly with a hair dryer to help it seat properly.

Note: Persistent door alarms can lead to high humidity and mold; resolve promptly.