Dishwasher stops and displays E4; machine may run the drain pump continuously and not accept new cycles.

Safety first: Unplug the dishwasher and close the water tap immediately to prevent further flooding.

• Check for visible leaks: Look around the base of the SMEG dishwasher for water on the floor. If present, dry the area and note where it seems to originate (door, side, rear).
• Drain base tray: Carefully pull the dishwasher out from the cabinet. Tilt it slightly backward (about 30°) to allow water in the base tray to run out onto towels. This may temporarily clear E4 but does not fix the leak source.
• Inspect hoses and clamps: Remove the side panels to access internal hoses. Check the circulation hose from the sump to the spray arms, the drain hose, and the inlet hose for splits, loose clamps, or rubbing damage.
• Check anti-flood float switch: In the base tray, locate the polystyrene float and microswitch. Ensure the float moves freely and is not stuck by grease or scale. Clean and dry the area thoroughly.
• Run a test with panels off: With the machine reassembled but side panels still removed, run a short cycle and watch for drips. If the leak source is not obvious or is from the tub seam, door liner, or heat exchanger, contact a professional technician.