Bosch dishwashers are typically trouble-free. As with any machine with movable parts, however, time and wear take their toil. If your Bosch dishwasher will not stop draining, try a few troubleshooting techniques before incurring the cost of calling a service technician.
Before you attempt any troubleshooting or repairs to your Bosch dishwasher, disconnect the dishwasher from the electrical power source. Either unplug the appliance from the wall outlet or shut off the electric power at the fuse or breaker box. You are working with an electrical appliance that retains water in the system. Always wear safety or rubber gloves and rubber soled shoes to avoid conducting electricity. Pick up tools by their insulated handle.
Bosch dishwashers are equipped with a float switch located underneath the appliance. The float switch is connected to a small plastic cylinder inside the dishwasher that "floats" upward and downward as the water level in the dishwasher fills or drains. If the float switch is defective, the float cannot move and the dishwasher will continue to attempt to drain, even when the water level is reduced. The float inside the machine cannot move if it is "trapped" or stuck because of sticky food residue, a buildup of mineral deposits or other small debris such as a toothpick or small fruit pit lodged in the dishwasher. Visually inspect the float and clean the float with soapy water and a soft brush.
Clean the drain filter in your Bosch dishwasher regularly. Food and other debris such as a piece of broken glass may be clogging the drain filter and preventing the machine from emptying. If the water cannot drain, the pump will continue to run. To clean the entire inside of your Bosch dishwasher, place a large glass bowl turned upward on the bottom rack of the dishwasher. The machine should be empty of all other dish or flatware items. Pour 3 cups of white distilled vinegar in the bowl and run the dishwasher on the "Power Scrub" cycle. The vinegar cuts through soap film and food residue. Your dishwasher will be sparkling clean and free of unpleasant food odors.
Consumers who own older models of Bosch dishwashers may have a model that has been recalled for safety concerns. On Jan. 15, 2009, Bosch Home Appliances and the U.S. Consumer Product Safety Commission issued a recall of 476,500 Bosch and Siemens model dishwashers because of a fire danger. The recall covers units manufactured from May 1999 to July 2005. Stop using the unit immediately and call the Bosch hotline or your Bosch dealer for a free repair if your unit is affected.