Dishwasher Not Cleaning Upper Rack? What to Check First

Give the water a clear path

When cups and bowls come out with food still attached, we'd check their placement before removing anything, because the load can interfere with both arm movement and water reaching the dirty surfaces. That makes loading a useful first check while everything is still sitting where it was during the wash.

The first possibilities to work through are obstructed spray-arm movement, dishes shielding one another from the spray, and debris in the filter. This is a practical checking order, not a ranking of how often each problem happens. Each gives you something specific to inspect before moving on.

Whirlpool's guidance for dirty top-rack dishes (opens in a new tab) points to loading, free spray-arm movement and a clean filter as the initial checks. Use those checks to work through what you can see, then use the cleaning method for your machine below.

Check the dirty surfaces and the arm's path

Look at the dirty side of each item, not just whether it fits between the rack supports. Place soiled surfaces down and inward toward the spray arms. Leave space between dishes and avoid stacking them, so the water has access to the surfaces that need cleaning.

Next, check that the spray arms can move freely with the dishes in their loaded positions. Reposition anything that blocks their movement. The useful result here is an unobstructed path around the arm, with no dish sitting where it interferes with that movement.

Spray access and arm clearance are related, but they answer different questions. An arm can have room to move while stacked dishes still hide dirty surfaces from the water. Looking at both helps you catch a crowded arrangement even when nothing is directly in the arm's way.

Poor placement can leave detergent as well as food soil on dishes, because the spray can't rinse those surfaces effectively. If you're seeing residue, include the arrangement of the load in your checks. Whirlpool's loading advice (opens in a new tab) explains why spacing and orientation matter to washing and rinsing.

Black or gray marks need attention too

Black or gray marks are another clue to look at how closely items sit together. Keep aluminum utensils and other aluminum items away from glasses and other dishes to help prevent those marks. Make that separation as you rearrange the load, alongside giving the spray room to reach each item.

This gives you a more useful way to describe what you're seeing than calling everything dirt. Food left behind and dark marks point you toward different details of the loading check. Whirlpool's advice on dish marks (opens in a new tab) specifically connects black or gray marks with items loaded too close together.

Follow your model's filter instructions

Food and other debris caught in the filter can affect washing performance, including leaving dishes less than clean. That's why this check belongs in the job even when the items you're unhappy with are upstairs. A well-arranged rack and a clean filter address different parts of the cleaning problem.

Before removing the filter, read your product manual's removal and cleaning directions. The method varies by model, so this is the point to use instructions for your own dishwasher. Follow its removal directions instead of treating the filter as a part that comes out the same way on every machine.

For the Whirlpool example, the filter-cleaning guidance (opens in a new tab) describes removing the filter from the bottom of the dishwasher and soaking it in warm, soapy water. If stubborn bits remain attached, gently scrub them with a soft-bristled brush.

The brush step is for the stuck-on debris that soaking leaves behind. Look at the filter as you clean it so you can see whether that buildup remains. For a Bosch dishwasher, use the running-water method in the next section, together with your machine's filter-removal directions.

Bosch dishwasher example for loading and the filter

On a Bosch dishwasher, pay particular attention to tall items anywhere in the load that could block the spray arms. Leave adequate space between items too. These are Bosch's loading checks for poor cleaning, so include the surrounding load when you're looking for what might interfere with the upper-rack wash.

The filter is at the bottom of the Bosch dishwasher. Before taking it out, use your owner's manual to find the removal directions for your machine. Bosch's filter guidance (opens in a new tab) makes that manual check part of the job, then gives the following cleaning sequence.

1. Wash the removed filter under running water with mild soap, looking for food or other debris on it.
2. Use a soft brush to remove attached debris, checking that the buildup comes away as you clean.
3. Reinstall the cleaned filter according to your owner's instructions, leaving it back in its installed position.

Keep filter care in your maintenance routine after this troubleshooting job. Bosch recommends cleaning it regularly to remove debris, and describes regular maintenance as a way to help the dishwasher clean thoroughly and efficiently. The purpose is to keep accumulated debris from being left in the filter.

Bosch dishwasher example for blocked spray holes

On a Bosch dishwasher, an arm's movement is only one part of the check. Debris can also be caught in its spray holes. Inspecting those openings addresses a blockage in the arm itself, separate from a tall dish obstructing its path through the load.

Use Bosch's spray-arm cleaning method (opens in a new tab): rinse the spray arms under water and look for any blocked holes. Where you find a blockage, use a toothpick to loosen the debris caught in that opening.

Keep the inspection focused on the holes as you work. The toothpick is for loosening trapped debris, and the visible result you're checking for is an opening that's clear of that debris. This cleaning step addresses the clog you can see in the spray arm.

If the upper rack still comes out dirty

Judge the cleaning result by the upper-rack dishes after washing. If food and residue remain after you've corrected the load and completed the applicable cleaning checks, consult your owner's manual for further assistance or contact an appliance technician for repairs. That's the point to move beyond these initial checks.

For a Whirlpool dishwasher, use the Customer Care service option referenced in Whirlpool's cleaning troubleshooting guidance (opens in a new tab) to schedule an appointment. Whirlpool directs owners to a professional technician when the cleaning problem continues after troubleshooting.

For a Bosch dishwasher in the US, call Bosch Customer Support at 1-800-944-2904. You can ask for further help or book a service visit if the problem persists. Bosch's US troubleshooting support (opens in a new tab) provides this contact for the next step after unsuccessful checks.