Dishwasher makes a loud banging or knocking noise during fill or drain.

Safety First: Turn off water and power before adjusting hoses.

• Secure hoses: Inspect the inlet and drain hoses under the sink and behind the dishwasher. Use clamps or straps to secure them away from cabinet walls.
• Install water hammer arrestor: If banging occurs when the valve closes, consider installing a water hammer arrestor on the dishwasher supply line.
• Check valve operation: Ensure the shutoff valve opens and closes smoothly; replace if it causes sudden pressure spikes.