Dirty water tank full icon and E04 error even when tank is empty, suction stops

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

• Clean the dirty water tank: Open the tank and locate the float mechanism. Rinse thoroughly with warm water to remove hair, lint, and detergent residue. Ensure the float moves freely up and down.
• Check for foam buildup: Excess detergent can cause foam that triggers the level sensor. Rinse the tank and reduce detergent concentration in future use.
• Inspect sensor components: If your model uses a magnetic float and reed switch, ensure the magnet is intact and the float is not waterlogged. For electronic sensors, gently wipe the sensor surfaces with a damp cloth.
• Check wiring: Follow the sensor wires from the tank area to the main harness. Ensure connectors are fully seated and not corroded.
• Reset and test: Refit the tank correctly, ensuring it is fully latched. Power on the unit and check if the error clears.

If the error persists, the level sensor or associated wiring may need replacement.