Display shows E4 and the unit stops; dirty water tank is full or recently emptied.

Safety first: Unplug the appliance before removing tanks or covers.

• Empty and rinse the dirty water tank: Remove the recovery tank and empty it completely. Rinse with warm water to remove foam, hair, and debris that may interfere with the float.
• Inspect the float mechanism: Locate the float inside the dirty water tank or lid assembly. Ensure it moves freely up and down. Clean any soap residue or lint that may cause sticking.
• Check the tank lid seal: Make sure the lid is properly seated and that any magnets or tabs used for level sensing are intact and aligned with the sensor in the base unit.
• Inspect wiring and sensor: Access the level sensor in the base (often a reed switch or micro-switch). Verify that the wiring harness is firmly connected and not corroded. Test the sensor with a multimeter while moving the float or magnet to confirm switching.
• Replace faulty parts: If the float is damaged or the reed switch does not change state, replace the dirty water tank assembly or the level sensor module as specified for your Rowenta model.