Dishwasher Not Cleaning Dishes? 8 Common Causes and Fixes
Poor wash performance is the most common dishwasher complaint. This guide covers spray arm clogs, water temperature, loading technique, and more.
1. Spray Arms Are Clogged
This is the most common cause. Remove the lower and upper spray arms (usually just unscrew or unclip them). Hold up to the light — the small holes should be clear. Use a toothpick to clear any blocked holes. Rinse under running water.
2. Water Temperature Is Too Low
Dishwashers need water at 120°F to properly dissolve detergent and remove grease. Set your water heater to at least 120°F. Run the hot water at the kitchen sink before starting the dishwasher to purge cold water from the supply line.
3. Overloading or Blocking Spray
Items blocking the spray arm rotation prevent proper coverage. Load with taller items on the outer edges and ensure nothing hangs below the rack and blocks the lower spray arm.
4. Detergent Issues
Use fresh detergent — old powder detergent clumps and loses effectiveness. Don't overfill the dispenser. Use rinse aid for better drying and spot prevention.
5. Dirty Filter
Remove the filter (twist counterclockwise in most dishwashers). Clean under running water with a soft brush. A clogged filter recirculates dirty water.
6. Hard Water Buildup
Mineral deposits clog spray arm holes and coat interior surfaces. Run a cleaning cycle with a dishwasher cleaner or citric acid monthly.
7. Insufficient Water Pressure or Fill
If the machine doesn't fill completely, water pressure during the wash cycle is too low. Check for fill errors or inspect the inlet valve.
8. Worn or Broken Spray Arm Bearing
The lower spray arm sits on a bearing that allows it to spin. If the bearing is worn, the arm doesn't spin properly. Replacement kits are inexpensive.