Open the door and inspect both the upper and lower baskets carefully. Confirm that no tall items such as large glasses, serving spoons, spatulas, or long-handled utensils are protruding above the basket edge or resting against the tub wall or door in a way that prevents the door from closing completely. Rearrange or remove any items causing an obstruction and try closing the door again.

Push the door closed using both hands placed flat on the outer door panel surface. You should hear and feel a solid, confident click as the latch hook engages in the catch plate. Once properly closed, there should be no visible gap between the door edge and the machine body anywhere around the perimeter.

With the door open, run your fingers slowly and carefully around the full rubber door seal, paying particular attention to the lower horizontal section which accumulates the most food debris. Remove any particles, grease residue, or solid material found. Wipe the seal clean with a damp cloth to remove grease films that prevent the door edge from seating flush.

Look closely at the plastic latch hook on the inner door edge — it must be completely intact with no cracks, chips, bending, or deformation. Inspect the catch plate opening in the machine body that the hook engages with. Both must be undamaged, properly aligned, and free of any debris lodged in the catch slot.

Open the door to its full horizontal position and check that it hangs level without dropping to one side. Apply gentle upward pressure on the outer edge of the open door and observe whether it lifts noticeably — this indicates worn hinge springs or hinge pin bushings. A door that sags will not engage the latch catch plate cleanly and produces intermittent i40 faults that become more frequent as the wear progresses.

Unplug the dishwasher from the mains and wait a full 60 seconds before plugging back in. Start a Quick Wash from a completely powered-off state without pressing any buttons before the machine initialises.