Your commercial dishwasher should drain automatically and if it doesn’t, there may be food clogging your filter, preventing drainage of the dishwasher. Your filter should be cleaned out often, and carefully. Follow instructions to clean out the filter so as to not cause any damage to the machine. You should also check that there are no kinks in the drain hose. It’s also advised to check the wash/rinse arms (and nozzles on the arms) to see if they are blocked. If you can’t identify the cause of the blockage, call a licensed professional.