De'Longhi dehumidifier displays F1 and stops; may be accompanied by beeping.

Safety first: Unplug the unit before removing the tank.

Step-by-step:

• 1. Remove and inspect tank: Take out the water tank and check the float mechanism. Ensure it moves freely up and down.
• 2. Clean float and guides: Remove slime or mineral buildup from the float and its guide rails using warm water and a soft brush.
• 3. Check magnet and switch: If accessible, locate the reed switch or sensor in the cabinet that detects the float magnet. Ensure it is not loose or corroded.
• 4. Reinstall tank correctly: Slide the tank back in firmly until it is fully seated. Confirm that the front panel closes flush.
• 5. Test operation: Plug in and power on. If F1 clears, monitor for correct shutoff when the tank fills.
• 6. Replace faulty components: If F1 persists, replace the float assembly in the tank or the water level sensor/reed switch in the cabinet.