Clean the filter and spray arms monthly to prevent clogs.
- Ensure water temperature is at least 120°F for proper detergent activation.
- Load dishes facing the spray and avoid blocking the arms.
- Run a maintenance cleaner every three months to remove grease and limescale.
- If cleaning doesn't improve, check the wash impeller or call a pro.
Why is my dishwasher leaving dishes dirty?
Several common causes lead to poor cleaning. A clogged filter traps food particles and reduces water flow. Spray arms with blocked holes fail to reach all dishes. Low water temperature prevents detergent from dissolving grease. A faulty wash impeller or circulation pump reduces water pressure. Hard water minerals can coat dishes and internal parts. Overloading or improper loading blocks water and detergent from reaching surfaces.
How to fix a dishwasher that isn't cleaning: step-by-step
First, unplug the dishwasher and remove the bottom rack. Twist the filter assembly counterclockwise and lift it out. Rinse the filter under running water, scrubbing with a soft brush. Check the spray arms for clogged holes; use a toothpick to clear them. Run a hot water tap in the sink to ensure the water heater is at least 120°F. Inspect the inlet valve screen for debris if water fills slowly. If the wash impeller is broken, replace it with a manufacturer part. Finally, run a cycle with a dishwasher cleaner to remove grease and limescale.
How to prevent dishwasher cleaning problems
Scrape large food scraps off plates before loading, but no need to pre-rinse. Clean the filter every month to prevent clogs. Run a maintenance wash with a cleaner every three months. Check the spray arms monthly for blockages. Use rinse aid to improve drying and reduce spots. Ensure the water heater is set to 120°F for optimal cleaning. Load dishes facing the spray, with large items on the sides.
When to replace your dishwasher or call a pro
If you've cleaned the filter and spray arms but dishes stay dirty, the circulation pump may be failing. A humming noise with no water spray often indicates a stuck impeller. Replacing a pump can cost more than half a new dishwasher's price. If the control board shows error codes, professional diagnosis is wise. A dishwasher older than 10 years with recurring issues may be cheaper to replace. Call a technician for electrical or water leak problems.