There are a few possible causes for a dishwasher that doesn't drain properly. Food clogging the drain mechanism or hose is one culprit. Dishwasher parts need to be clear and free of debris to work properly! Another possible cause of a poorly draining unit is something called a 'drain solenoid'. Some washers use this, and they can sometimes get stuck. You don't need replacement parts here, either--just use a hand to unstick it and try again. Yet another cause? You could have a stuck motor. Again, try unsticking it by hand. If none of these tips work, you may have more serious problems. Bosch dishwasher parts and other brands are easy to come by once you determine what the real issue is. Many times it is a system of trial and error to find out what's wrong with your machine and order the appropriate dishwasher replacement parts.