Dishwasher stops and shows E04; often associated with poor or no water circulation and sometimes overfilling.

Safety first: Disconnect power and close the water tap before removing any panels.

• Inspect side water matrix: Remove the left side panel. Check the transparent water matrix (water distributor) for heavy limescale or sludge. If heavily clogged, it can cause incorrect water level readings.
• Clean the matrix and hoses: If accessible, remove the hoses from the matrix and rinse them. Use warm water and a soft brush to clean visible deposits. Do not use sharp tools that may puncture plastic parts.
• Check pressure chamber/air trap: Locate the small chamber and hose leading to the pressure switch. Clean any grease or residue that may block air movement.
• Run a cleaning cycle: Reassemble, then run a hot intensive cycle with dishwasher cleaner or white vinegar (in a dishwasher-safe cup) to help dissolve internal deposits.
• Professional diagnosis: If E04 persists, the flow meter or pressure switch may be defective and should be tested and replaced by a technician.