Pressure relief system for a dishwasher pump assembly

A dishwasher includes a filter chamber having a pressure relief system. The filter chamber preferably includes two drain ports, a first that leads to a drain line through a drain pump, and a second that leads directly to the drain line for over-pressure relief. The drain line is formed with a loop that establishes a pressure head. In the event that the filter chamber becomes clogged, a pressure build-up will occur. If the pressure in the filter chamber exceeds the pressure head in the drain line, a siphoning action will be automatically triggered that evacuates the washing fluid from the filter chamber. In this manner, the filter chamber can be purged through operation of the drain pump or, in the event of a clog resulting in an over-pressure condition, by siphoning the wash fluid directly into the drain line.