Unplug the dishwasher from the mains before opening the door or reaching inside. If the machine stopped mid-cycle there may be hot water and steam in the tub. Open the door slowly and stand to one side to allow steam to escape before leaning in. Have a towel ready to absorb any water in the tub base.

Remove the upper spray arm by pulling it upward off its mounting post or by unscrewing it anti-clockwise. Remove the lower spray arm the same way. Hold each under warm running water and use a toothpick, cocktail stick, or wooden skewer to clear every spray hole individually around the full circumference of each arm. Even one or two blocked holes significantly reduces circulation pressure and forces the pump to work harder.

Remove both the cylindrical coarse filter and the flat fine mesh filter. Clean both thoroughly under warm running water using a toothbrush. With the filters removed, shine a torch into the sump cavity and examine the area carefully for any foreign objects — glass fragments, fruit stones, small bones, bottle caps, or pieces of crockery that may have passed through the tub during a previous cycle.

With filters removed and the sump visible, try to rotate the circulation pump impeller gently using a non-metallic implement such as a wooden cocktail stick. The impeller should rotate with smooth, even, light resistance through a full turn. Any catching, grinding, or inability to move at all indicates a foreign object jammed around or between the impeller blades.

With the upper spray arm removed, check the central tower that feeds water to the upper rack. This is typically a vertical tube running from the back wall of the tub to the upper rack connection point. Confirm it is fully connected at both ends, not cracked or split, and completely clear. A blocked wash tower prevents water reaching the upper spray arm entirely while the pump continues to run, which can produce i50.

Refit all spray arms, filters, and any components removed. Plug in and run the hottest available programme. Remain present and listen during the wash phase. You should hear a continuous, strong, steady rushing sound of water being pumped at pressure throughout the wash phase.