Patent ID: 7789968

Claim:
A dishwasher comprising: a tub having bottom, opposing side, rear and top walls which collectively define a washing chamber adapted to receive and cleanse soiled kitchenware; at least one wash arm for spraying washing fluid onto kitchenware placed into the washing chamber; a pumping unit, including a motor, for directing washing fluid to the at least one wash arm; a filter chamber, adapted to receive a portion of the washing fluid, for entrapping soil from the washing fluid while permitting cleansed washing fluid to be directed back into the washing chamber; a drain exposed to the filter chamber; means for sensing a plurality of dynamic operating parameters of the dishwasher, with the plurality of dynamic operating parameters including at least one fluid dynamic operating parameter and a current of the motor; and means for performing both an unscheduled drain operation, based on the plurality of dynamic operating parameters, and at least one timed drain operation for the dishwasher during an overall dishwashing cycle.