Quick Answer
If your dishwasher is leaving food on dishes, check the filter, spray arms, loading pattern, detergent, rinse aid, water temperature, and selected cycle. Most cleaning problems come from blocked water flow, poor loading, clogged filters, low water temperature, hard water, or weak detergent. If dishes are still dirty after basic cleaning, the issue may involve the wash pump, inlet valve, heating system, diverter, sensor, or control board.
Symptoms at a Glance
Food stuck on plates
Likely cause: Poor loading, weak spray, clogged filter, or light cycle.
Homeowner action: Scrape large food and clean the filter.
Grit on glasses or bowls
Likely cause: Dirty filter, blocked spray arms, or food redepositing.
Homeowner action: Rinse the filter and inspect spray arm holes.
Detergent still in dispenser
Likely cause: Blocked dispenser door, bad detergent, low water, or control issue.
Homeowner action: Make sure dishes do not block the dispenser.
Top rack dirty, bottom rack clean
Likely cause: Upper spray arm blockage, diverter issue, or poor water pressure.
Homeowner action: Check upper rack loading and spray arm movement.
Dishes dirty plus standing water
Likely cause: Drain restriction, clogged filter, or pump problem.
Homeowner action: Review [dishwasher won't drain](/dishwasher-wont-drain/) guidance or schedule service.
Repair Difficulty Meter
DIY difficulty: Low for filter cleaning, spray arm checks, loading changes, detergent review, and rinse aid refilling.
Estimated time: 20-45 minutes for safe homeowner checks.
Tools needed: Soft brush, toothpick, towel, flashlight, owner's manual, and rinse aid if needed.
Safety risk: Moderate because dishwashers use hot water, electricity, sharp debris, and moving spray components.
When to call a professional: Call when cleaning does not improve, spray arms do not move, water does not fill or heat, grinding occurs, leaks appear, or error codes repeat.