A Bosch dishwasher E15 error usually indicates that the leak protection system has detected water in the base pan. The dishwasher may keep draining or refuse to start because the float switch is active.

Before doing anything else, turn off the dishwasher and check for visible water around the appliance, under the door, and near the supply and drain connections. Avoid repeatedly resetting the dishwasher if water is still present.

Common causes include a loose hose, leaking sump seal, damaged water inlet, over-sudsing, cracked spray arm, or drain issue. A technician can remove panels safely, dry the base, find the source of the leak, and test the dishwasher before it is used again.