Why Is My Dishwasher Making Noise? Sounds Explained and Fixed

Dishwashers make noise during normal operation — but some sounds signal a problem. Here's how to tell the difference between normal dishwasher sounds and noises that need attention, and what to do about each.

Normal Dishwasher Sounds (Nothing to Worry About)

• Humming: The motor and pump running — completely normal
• Swishing or whooshing: Water spraying from the spray arms
• Clicking: The detergent dispenser opening or the timer advancing
• Draining sounds: Water being pumped out at the end of the cycle
• Knocking (light): Dishes or utensils shifting slightly during the wash

Noises That Signal a Problem

1. Loud Grinding or Crunching

A grinding sound usually means something hard — a piece of glass, a bone, or a small utensil — has fallen into the pump area or is caught in the spray arm.

Fix: Stop the dishwasher immediately. Remove the bottom rack and check the pump area and spray arms for foreign objects. Remove any debris carefully. Check that all items are loaded securely and nothing can fall through the rack.

2. Loud Banging or Thumping

Banging usually means dishes or utensils are knocking against each other or against the spray arms during the cycle.

Fix: Reload the dishwasher. Make sure tall items aren't blocking the spray arms, and that glasses and cups are secured between tines. Give the spray arms a spin by hand before starting — they should rotate freely.

3. High-Pitched Squealing or Squeaking

A squealing sound often indicates a worn or failing wash pump motor or drain pump motor bearing.

Fix: This typically requires pump motor replacement. If the squealing is new and persistent, call a technician to assess the pump.

4. Loud Buzzing

A buzzing sound during the drain cycle is usually the drain pump working hard — often because of a partial blockage in the drain line or filter.

Fix: Clean the filter and check the drain hose for blockages. Run a cleaning cycle with Affresh Dishwasher Cleaner Tablets (amzn.to/42P5MKQ) to clear buildup from the pump and hoses.

5. Rattling

Rattling is almost always caused by loose items in the dishwasher — a utensil that's fallen through the rack, a lid that's flipped over, or a lightweight item that's moving around.

Fix: Check that all items are secured. Make sure the cutlery basket is properly seated. Secure lightweight plastic items between tines so they can't move.

6. Water Hammering (Banging Pipes)

A loud bang or thump in the walls or pipes when the dishwasher fills or stops filling is "water hammer" — caused by water pressure suddenly stopping in the pipes.

Fix: This is a plumbing issue, not a dishwasher issue. A plumber can install a water hammer arrestor to solve it.

7. Loud Humming That Doesn't Stop

If the dishwasher hums loudly but doesn't seem to be washing or draining, the pump may be jammed or the motor may be failing.

Fix: Check the pump area for debris. If clear, the motor may need professional assessment.

Prevent Noise Issues

• Always check that spray arms spin freely before starting
• Secure all items properly — nothing should be loose enough to fall through racks
• Clean the filter monthly to prevent pump strain
• Run a monthly cleaning cycle with Affresh Dishwasher Cleaner Tablets (amzn.to/42P5MKQ) to keep the pump and hoses clear
• Use quality detergent — the Finish Powerball Dishwasher Pods (amzn.to/3RE929j) are pre-measured and won't cause excess suds that stress the pump

Quick Sound Diagnosis