Siemens 8503 dishwasher still has water in it when the cycle has finished and I can't undo the screws to have a look at the water pump. The screws are not the standard phillips type and seem to be hexagonal do you have to have a special tool for this?
If not a straight sided hexagon socket headed screws for which you use an allen key, but have slightly curled sides, they are probably Torx and you can buy sets of the bits which will fit them at a good DIY shop
