Patent ID: 7404864

Claim:
A method of pumping and filtering through first, second, third and fourth filter units, washing fluid during a washing operation in a dishwasher having a tub, a recirculation pump and at least one wash arm comprising: directing washing fluid filtered by the first and third filter units directly to the recirculation pump; directing the washing fluid filtered by the second filter unit to a first filter chamber; storing soil particles filtered by the third filter unit, located in the first filter chamber, in a first soil collection chamber; outputting washing fluid from the recirculation pump and delivering the washing fluid to the at least one wash arm through a conduit that extends through a second filter chamber incorporating the fourth filter unit; bleeding off a portion of the washing fluid from the conduit within the second filter chamber such that a portion of the washing fluid output by the recirculation pump is delivered to the fourth filter unit; storing soil particles filtered by the fourth filter in a second soil collection chamber; and initiating a drain operation to purge the first and second soil collection chambers of soil particles during a washing operation, with the drain operation including opening a seal member for the second soil collection chamber through a pivoting arm of a valve assembly to communicate the second soil collection chamber with the first soil collection chamber.