Display shows E04 and the unit stops; dirty water tank is not full but the machine behaves as if it is.

Safety: Unplug the carpet cleaner and remove both clean and dirty tanks.

• Inspect float mechanism: Open the dirty water tank and locate the float (usually a plastic piece that moves up as the tank fills). Clean off hair, lint, and detergent residue. Ensure it moves freely up and down.
• Clean sensor contacts: If your Vileda model uses metal level electrodes, wipe them with a damp cloth and a mild detergent to remove film that may cause false readings.
• Check wiring: Follow the small harness from the tank area to the main body. Ensure the connector is fully seated on the PCB and that no wires are pinched or broken.
• Reset the error: Reinstall the tank correctly, making sure it is fully seated and the lid is closed. Power on and test. If E04 persists, the level sensor circuit on the PCB may be defective and the board may need replacement.