Dishwasher overfills or repeatedly drains and refills; E4 is displayed and the cycle stops.

Safety first: Unplug the appliance and close the water tap. Be prepared for water spillage when opening panels.

• Check for excessive foam: If incorrect detergent (e.g., hand dishwashing liquid) was used, foam can trigger overfill errors. Run a rinse cycle without detergent after allowing foam to dissipate.
• Inspect pressure chamber and hose: Access the side of the tub (remove side panel). Locate the small pressure hose running from the sump or side chamber to the pressure switch. Remove the hose and blow through it to clear blockages. Rinse the chamber with warm water to remove grease and debris.
• Test the pressure switch: With the hose removed, gently blow into the switch and listen for clicks. If no click or if it rattles loosely, the switch may be defective.
• Check inlet valve operation: If water continues to enter even when the machine is off, the inlet valve is stuck open and must be replaced immediately.
• Reassemble and test: Refit the hose securely, restore power and water, and run a short cycle. If E4 persists, the level sensor or control board may require replacement.