Replace the dishwasher’s inlet valve
If the dishwasher is not cleaning dishes even after completing the troubleshooting above, the inlet valve—which allows water to flow into the dishwasher—could be failing. A hammering noise during a cycle would indicate the problem.
At this point, many homeowners opt to call a technician, but if you’re the DIY type, consult your owner’s manual. It will list the replacement valve you’ll need to order and may offer instructions on how to replace the old one.