I have a Prima 450 slimline integrated dishwasher.Today it became bunged up so i put in some hot water,used plunger that seems to clear the water.I topped up the salt and rinse aid etc and Bobs ya Uncle-wrong. It now bleeps 31 times, the pump runs and empies any water in the machine then stops. I've tried holding buttons down for 3 secs,turn off for 30 etc but nothing.Any ideas please?