Dishwasher displays F9; unit may overfill or leak from the door.

Safety first: Immediately turn off water supply and power if the dishwasher is overfilling.

• Check water inlet valve: With power off but water on, see if water continues to enter the tub. If so, the inlet valve is mechanically stuck open and must be replaced.
• Inspect drain hose routing: Ensure the drain hose has a proper high loop or air gap above the sink drain to prevent siphoning.
• Check level sensor: Inspect and test the float or electronic level sensor as in F6. Replace if faulty.
• Control board: If the valve only overfills when powered and the sensor is good, the main control board may be failing to shut off the valve and should be replaced.