Pressure relief system for a dishwasher pump assembly

A dishwasher comprising:

• a tub having a bottom and a plurality of side walls that collectively define a wash chamber, said wash chamber establishing a sump;
• a recirculation pump fluidly connected to the sump for establishing a flow of washing fluid in the wash chamber;
• a drain pump fluidly connected to the sump for selectively purging washing fluid from the wash chamber;
• a drain line fluidly connected to the drain pump, said drain line including a drain loop that establishes a pressure head;
• a filter chamber provided on the tub for filtering the washing fluid and collecting particles;
• a first drain means fluidly connected to the filter chamber, said first drain means directing the particles from the filter chamber, through the drain pump and into the drain line;
• a second drain means fluidly connected to a lower portion of the filter chamber, said second drain means directing the particles from the filter chamber directly to the drain line, while bypassing the drain pump, when a pressure in the filter chamber exceeds the pressure head in the drain loop;
• and
• a third drain means, separate from the first drain means, fluidly connected between the sump and the drain pump.

A method of draining a filter chamber in a dishwasher having a drain line provided with a drain loop that establishes a pressure head in the drain line comprising:

• pumping a recirculating flow of washing fluid into a wash chamber;
• filtering the flow of washing fluid;
• collecting particles filtered from the flow of washing fluid in a filter chamber;
• and
• removing the particles from the filter chamber by:
• a) draining the particles from the filter chamber, through a drain pump, wherein the particles are directed into a drain line;
• and
• b) purging particles from a lower portion of the filter chamber directly to the drain line, while bypassing the drain pump, when a pressure in the filter chamber exceeds the pressure head in the drain line.