My Zanussi ZSF4123 dishwasher has stopped cleaning plates properly. It makes everything wet but at the end of the cycle the detergent block is half dissolved at the bottom. I have just run a cycle and opened the door during this. The bottom is full of soap suds and water and the top spray bar is dripping water after I open the door but when I close and then reopen a few secs later the top spray bar has definetly not rotated. The water is also not hot, this dishwasher is a cold fed only machine so I guess the element inside must not be doing it's job too?? Any ideas??