Dehumidifier shows E9 and stops, often shortly after starting

Safety: Disconnect from mains before removing the water tank or accessing internal components.

Steps:

• Check tank position: Remove and reinsert the water tank firmly. Ensure it is fully seated and not warped.
• Inspect float: Look inside the tank for a plastic float. Make sure it moves freely up and down and is not jammed by dirt or scale. Clean with warm soapy water and rinse.
• Test float switch: On many models, a magnet in the float activates a reed switch or sensor in the body. With the unit unplugged, locate the water level sensor behind the tank area. Check that it is securely mounted and the wiring is intact.
• Simulate tank full/empty: With the tank removed and unit unplugged, carefully move the float or place a magnet near the reed switch while measuring continuity across the switch with a multimeter. It should change state as the magnet approaches.
• Replace faulty parts: If the reed switch or sensor does not change state, replace the water level sensor / float switch assembly. If the float is waterlogged or cracked, replace the tank or float.
• PCB check: If the sensor and float are good but E9 persists, the main control PCB may misread the level and require replacement.