It took several weeks to find the very slow leak. Was getting E15 error code & water trap error once a week. I would remove water from bottom case to clear the E15 code. Then about a week later the E15 code would trigger. I discovered a leak between the circulation pump and the sump assembly housing. I replaced the circulation pump heater assembly. Also replaced the check valve while I had dishwasher apart. The repair time was 2 hours. Thanks, Dave in CT.