De'Longhi dehumidifier shows P1 and stops; water tank may be empty or partially full.

Safety first: Unplug the unit before accessing the pump tray or internal tank. Water and electricity are a hazard together.

Step-by-step:

• 1. Check external tank: Remove and empty the main water tank. Clean any slime or debris, then reinstall it correctly so it engages the tank switch.
• 2. Inspect pump hose (if equipped): If your De'Longhi model has a continuous drain pump, check the discharge hose for kinks, clogs, or a frozen outlet. Clear any blockage and ensure the hose slopes downward.
• 3. Access internal pump tray: Remove the rear or side panel to locate the small internal reservoir and pump. Carefully sponge out any standing water.
• 4. Clean float and tray: Locate the float switch in the pump tray. Clean off slime, scale, or debris that may prevent it from moving freely. Rinse the tray with warm water and mild detergent, then dry.
• 5. Test pump operation: With the unit reassembled, pour a small amount of water into the tray (if accessible) and power on. Listen for the pump running and check that water is discharged through the hose.
• 6. Replace faulty components: If the pump does not run or the float switch does not change state, replace the condensate pump assembly or float switch as appropriate.