Dishwasher Not Cleaning Dishes: Causes and Fixes

When a dishwasher stops cleaning, the cause is usually something you can fix in a few minutes: a clogged filter, blocked spray arm holes, dishes loaded so they block the water, or water that isn't hot enough for the detergent to work. If dishes are still dirty after those checks, a technician should look at the wash motor, heating element, inlet valve or detergent dispenser.

Read the dirt before you fix it

What's left on the dishes is a clue. Bits of food usually point to the filter, spray arms or loading. A gritty or chalky film usually points to hard water or detergent that didn't dissolve. Detergent still sitting in the cup points to the dispenser or to a dish blocking its door. Wet, spotted glasses are often a drying and rinse aid issue instead, covered in our guide to a dishwasher not drying.

Start with power off

Unplug the dishwasher or switch off its circuit breaker before you reach into the tub or remove parts, as Whirlpool advises before any inspection. Everything in the next section can be done from inside the tub. If you end up looking under the tub or behind the kick panel, also close the dishwasher's water supply valve. GE says it is usually under the kitchen sink on the line feeding the dishwasher and closes clockwise; with no working valve there, shut the main water supply to the house.

What to check yourself

1. Clean the filter

This is the most common fix. Bosch points to the filter first when dishes aren't getting clean, and Amana treats food left on dishes as a sign the filters need cleaning. Twist out the filter at the bottom of the tub, rinse it under running water, and gently scrub the mesh. KitchenAid recommends doing this every three to six months on average, more often if you load heavily soiled dishes without pre-rinsing.

2. Clear the spray arms

Hard water and food bits block the small holes in the spray arms. GE suggests clearing blocked jets with a paper clip or tweezers without damaging them, and Bosch suggests a toothpick. Beko recommends taking the arms off and brushing out the holes under running water. After you put them back, spin each arm by hand to make sure nothing stops it.

3. Fix the loading

Water has to reach every surface. KitchenAid says to load dishes with the soiled side facing down and not overcrowd. Bosch warns that tall items can block the spray arms, and LG says dishes shouldn't overlap. Scrape off large scraps first. You don't need to pre-rinse, and ENERGY STAR notes pre-rinsing increases total water and energy use.

4. Check the water temperature

Detergent needs hot water. KitchenAid says water should reach the dishwasher at about 120°F, and Bosch suggests setting the water heater to roughly 120 to 125°F. GE and Maytag both recommend running hot water at the kitchen sink before starting a cycle so the dishwasher fills with hot water instead of what was sitting in the pipes. GE also says to confirm the dishwasher is connected to the hot water line.

5. Check the detergent and rinse aid

Use fresh automatic dishwasher detergent. KitchenAid says to clean caked-on detergent out of the dispenser and keep detergent sealed so it doesn't clump. Whirlpool warns that dish soap, hand soap or laundry detergent causes over-sudsing. Keep rinse aid filled, which helps with spots and film.

6. Pick the right cycle

Frigidaire notes that Rinse, Quick Wash and 30-minute cycles are not meant for heavy soil. Use a normal or heavy cycle for dirty loads.

7. Deal with hard water film

A white, cloudy film often comes from minerals, not food. Maytag suggests removing hard-water film with affresh or a white vinegar rinse and considering a water softener for very hard water. GE recommends running an empty hot cycle with a dishwasher cleaner to remove grease and lime scale from the filters, spray arms and internal piping.

What a technician tests

If the dishwasher still leaves food on dishes after the checks above, a part is probably not doing its job. A technician typically looks at:

• Wash motor and pump. This motor pushes water through the spray arms. A weak or failing motor means low spray pressure even with clean arms.
• Water inlet valve. A valve that doesn't open fully lets in too little water. Maytag says to confirm the household water valve is fully open first.
• Heating element and thermostat. If the water isn't being heated during the cycle, cleaning suffers along with drying.
• Detergent dispenser. A dispenser door that doesn't open leaves the detergent in the cup. Samsung's troubleshooting says to confirm detergent is actually dispensing and dissolving.
• Drain problems. Dirty water that doesn't fully drain can redeposit food on dishes. See our guide to a dishwasher not draining.
• Installation. GE's wash-performance checklist starts with whether the unit is level, on the hot water line, and has its drain hose no higher than 72 inches.

When to stop and call a pro

• The filter and spray arms are clean, loading is right, and dishes are still dirty.
• The detergent is still in the dispenser at the end of the cycle.
• The tub isn't filling with much water, or the water stays cold.
• You hear grinding or humming, or the spray arms don't turn during a cycle.
• An error code appears and returns after a power reset.

Don't remove the kick panel to test parts with the power on. The motor, valve and heater all involve live wiring next to water lines.

What the repair might cost

A wash motor on an older machine is often the point where replacement makes more sense. Our repair or replace guide explains the rules of thumb, and the dishwasher repair cost guide has the full list of parts.

Brand-specific help

Each brand's filters and spray arms come apart a little differently. Our pages for Bosch, GE, LG and Frigidaire cover common problems and local companies, and every brand is on our brands page. You can also search the dishwasher repair directory for technicians near you.