Why Your Dishwasher’s Top Rack Is Not Cleaning

Why Your Dishwasher’s Top Rack Is Not Cleaning

Nobody likes to manually wash dirty dishes. That is why it can be frustrating when your bowls and glasses on the top rack come out unclean even after running a cycle in your dishwasher.

So why are your top rack dishes not cleaning and how can you solve it? Let’s jump right into the answer.

Why is your dishwasher’s top rack not cleaning?

Your dishwasher’s top rack won’t clean if they are loaded incorrectly, the water supply is low or cold, or the interior parts are dirty. A broken seal or clogged spray arm can also be an issue.

To fix it, reload all the dishes correctly and verify that your dishwasher is getting enough water and heat.

If the problem remains, try the following steps:

  • Clean the interior walls, rubber seal, and filter assembly of your dishwasher.
  • Check the spray arm’s seal and make sure that it isn’t misaligned or broken. Replace the seal if necessary.

If you need more guidance, keep reading below to learn more about how to perform these troubleshooting methods step-by-step.

Important Note: Unplug your dishwasher before performing any of the suggested repairs. Press the power button and make sure that the dishwasher no longer lights up.

Causes and Solution

There are 5 common causes why your dishwasher’s top rack items aren’t cleaned after a cycle:

1. The dishes have been loaded incorrectly.

2. The water supply is low or cold.

3. The spray arm’s seal is broken.

4. The top spray arm is clogged.

5. The interior of the dishwasher is dirty.

Here are a few quick suggestions on how to solve these issues.

Incorrectly Loaded DishesRemove all your dishes and other items from the racks. 

Place larger items on the top rack and smaller items on the bottom.

Make sure to leave enough space in between your dishes. Do a second cycle if necessary.
Water Supply ErrorOpen your kitchen sink’s faucet and make see if your home is getting enough water. 

Check your plumbing or your dishwasher’s water inlet valve if you are getting a low-level water issue.

Set your water temperature at the recommended level. 

If your dishwasher has a heating component, test it for continuity and replace it if damaged.
Broken Spray Arm SealRemove the top rack and access the top spray arm. Inspect the arm seal for misalignment or damage. 

Push the seal back in place or replace it if necessary.
Clogged Top Spray ArmRemove the top rack and uninstall the top spray arm. 

Soak the spray arm in white vinegar overnight and rinse it after.

Use a toothpick or a needle to clean the openings of the nozzle. 

Run some water in the opening and make sure that it runs freely.
Dirty Dishwasher InteriorUnplug your dishwasher and pull out all the removable items. Clean the interior walls, racks, and baskets.

Remove the filter assembly and wash it thoroughly. Reinstall everything back once they have been cleaned.

Incorrectly Loaded Dishes

One of the likeliest reasons your top rack dishes are unclean after a cycle is that you have loaded your dishes incorrectly.

An unwashed top rack is commonly due to the error of placing large items on the bottom rack instead of the upper rack.

If your dishwasher only has one spray arm located at the bottom of your dishwasher, large items such as trays and pots will block the water from getting into the top dishes.

It is also possible that your items such as plates, bowls, spoons, and forks are nested together, stacked too closely, or facing the wrong way, leaving them dirty after the cycle.

Solution: Follow the steps below to learn how to load your dishes correctly.

  • Step 1: Take out all the items on both racks.
  • Step 2: Place all the dishes on the top rack if you are only washing a few.
  • Step 3: Plan ahead to determine the best loading pattern. Consider the sizes, shapes, and number of your washables before loading them. 
  • Step 4: Utilize your dishwasher’s features and possible configurations.
  • Step 5: Remove large leftover food debris such as bones, meat chunks, or seeds. Avoid pre-rinsing your items to avoid white films on your transparent items. 
  • Step 6: Place the dishes so that the dirtiest side is facing the center of the dishwasher.
  • Step 7: Position concave items such as bowls and pots face down so water can be sprayed into them.
  • Step 8: Make sure there is enough space between your dishes and that the items aren’t nested together.
  • Step 9: Load large items such as pots and pans on the bottom rack.
  • Step 10: Place smaller items such as saucers, mugs, glasses, and other dishwasher-safe plastic items on the top rack.
  • Step 11: Use the glass support rack for your stemware. Fold it if not in use.
  • Step 12: Use the cutlery basket for your utensils. Make sure that your spoons and forks are not on top of each other.
  • Step 13: Load your spoons and forks with the handles down. Load knives the other way around (handles up).
  • Step 14: Make sure to secure smaller items so they come loose during the cycle.
  • Step 15: Make sure that no items are sticking out of the racks so they don’t bump against the water nozzles when they are moving or spinning.

Water Supply Error

Both the amount and temperature of your water supply are essential in cleaning your dishes properly.

If they don’t meet the minimum requirement of your dishwasher, this will affect your dishwasher’s cleaning performance significantly.

Here are some of the reasons your water supply may be causing your top rack dishes to stay uncleaned.

 Low Water Supply

Water supply plays an important role in cleaning your dishes since it directly affects the force of the water that’s coming out of the nozzle.

Strong water pressure helps in removing greases and sticky leftover food in your dishes. 

However, if your water supply is low, this will also dampen the cleaning ability of your spray arms.

A weak water supply may also not have enough force to reach the top rack. This is usually the case for dishwashers with only one nozzle at the bottom of the tub.

Clogs or damage in the water inlet valve is the prime cause of this problem. Plumbing issues, a malfunctioning control board, or a faulty float switch are also likely culprits.

Solution: First, open your kitchen sink faucet and see if your home is getting enough water. 

If the flow is fine, next, check your water inlet valve for clogs and signs of damage that may be restricting the flow of water in your dishwasher.

Disconnect the inlet hose from the water inlet valve and turn on the water supply tap. Check if water can flow freely from the supply to the open end of the inlet hose.

If it’s clogged, uninstall the inlet valve and hose and make sure to remove any hard water minerals, dirt, and other debris that are causing the blockage.

Also, straighten any irregular bends on the water inlet hose and make sure that its connections are tight on both ends.

Test the water inlet valve for continuity and verify that the entry port isn’t partially closed. Replace the entire water inlet valve assembly if it’s damaged.

Since there are other causes of a low-level water supply, here’s a complete list of its causes as well as how to troubleshoot them.

Partially Closed Shut Off ValveLocate the water supply tap and make sure that it is fully open.
Low Water Pressure/ Plumbing IssuesTest your water pressure at home by opening one of the faucets. 

If the pressure is low, inspect for any plumbing issues.
Malfunctioning Control BoardUnplug your dishwasher for about 10 – 15 minutes. Plug it back in and reboot it.
Faulty Float SwitchMake sure that the float switch can move freely. You can also clean the float switch and the water fill reservoir.
Clogged or Bent Water Inlet LineCheck that the water supply hose isn’t kinked or twisted. 

Also, make sure that your dishwasher is using a 3/8 water line.
Malfunctioning Water Inlet ValveTest the water inlet valve for continuity. If the valve is damaged, you’ll need to replace it.
Low Drain HoseMake sure your drain hose has a high enough loop so the water does not go straight to draining.

Low Water Temperature

Most dishwashers prefer a hot water supply to improve their cleaning performance.

This is why some dishwashers have a built-in heating component or are connected to water heating systems to regulate the water temperature.

If your dishwasher is connected to a cold water supply or has a faulty or weak heating element, this may leave some of your top rack dishes unclean since they are positioned farther from the metal rod below. 

Solution: If your dishwasher has its own heating rod, first, unplug your dishwasher and remove the lower rack to access the heating component.

Look for breaks, blistering, and discoloration in the metal rod. If the rod seems to be in good condition, perform a resistance reading to make sure that it’s working correctly.

To do this test, follow these steps

  • Step 1: Unplug your dishwasher and remove the heating rod. Set it aside somewhere you can perform the test safely.
  • Step 2: Adjust the range selection dial of your multitester to the lowest setting of ohms of resistance.
  • Step 3: Touch the probes together to calibrate the meter. Adjust the needle to zero while you’re calibrating.
  • Step 4: Use the probes to touch both ends of the heating element.
  • Step 5: Check the reading in your tester. A working heating element should give a reading between 0 to 50 ohms of resistance. 

Replace the heating element if the needle does not move significantly or at all.

If you are using a water heating system for your dishwasher, read your dishwasher’s manual to learn the recommended temperature setting.

Broken Spray Arm Seal

Most spray arms have a seal that stops the water from leaking anywhere except in their openings. 

This helps in increasing the water pressure jetted out of your dishwasher’s spray arm which helps wash heavily greased and oily dishes.

However, if the seal is broken, the water that is supposed to be shot out of the top spray arm will leak elsewhere instead, leaving your top rack dishes still dirty after the cycle.

Solution: To inspect and replace the spray arm seal, follow the steps below:

  • Step 1: Pull out the upper rack and set it aside on a flat and solid surface.
  • Step 2: Access the top spray arm of your dishwasher. If the spray arm is located beneath the top rack, flip the rack over to uninstall the spray arm.
  • Step 3: Unthread the screw holding the spray arm and lift the tube off of the center spindle to detach it from the spray arm.
  • Step 4: Disconnect the spray arm from the tube.
  • Step 5: Remove the old seal from the spray arm and replace it with a new one.
  • Step 6: Reinstall the spray arm back on the spindle and reattach the tube. Screw the spray arm back on the rack.
  • Step 7: Slide the rack back inside the dishwasher and reattach the stop clips to the tracks.

Clogged Top Water Nozzle

Another possible reason why your top rack dishes are not clean after a cycle is that the water nozzles themselves are dirty.

Leaving the water nozzles unclean for too long can leave small food particles or detergent suds lodged in its openings.

Dirt and grimes can then be sprayed directly onto your dishes during the wash or rinse cycle, causing the problem.

Solution:  To fix this, you’ll need to clean the water nozzles in your dishwasher. To do this, perform the following steps:

  • Step 1: Unplug your dishwasher.
  • Step 2: Pull out the bottom rack and baskets to access the nozzle.
  • Step 3: Remove the nozzle cap by turning it counterclockwise. If your dishwasher has an upper spray arm, unscrew it from the underside of your top rack and detach it from the tube.
  • Step 4: Clean the nozzles thoroughly using a dishwasher brush or old toothbrush.
  • Step 5: Soak the nozzles in distilled white vinegar overnight then rinse them in running water.
  • Step 6: Inspect the nozzles’ openings and make sure that water can flow freely.
  • Step 7: Reinstall the bottom nozzle by turning the cap clockwise. Screw the upper spray arm back on the top rack and reconnect the water tube.
  • Step 8: Check if you have installed the nozzles correctly by spinning them.

Dirty Dishwasher Interior

The last possible reason why your top rack dishes are not cleaned is because of a dirty dishwasher interior.

All interior components of your dishwasher are vulnerable to dirt and oil build-up. This includes the door rubber seal, racks, baskets, walls, and the drain filter assembly.

When these components are not cleaned regularly, stuck food grimes and fatty oils can break down during the cycle and stick to your dishes instead.

Solution: First, run a cleaning cycle to wash your dishwasher’s interior. Check your dishwasher’s manual on how to run a cleaning cycle or sanitize cycle.

Remove all the items in your dishwasher and use a cleaning agent such as a dishwasher cleaning tablet, chlorine-based detergent, or even a cup of white vinegar.

However, avoid using vinegar and detergent at the same time. Also, do not use bleach on dishwashers with stainless steel interiors as this can cause discoloration or damage.

Cleaning the interior parts of your dishwasher manually is also a good way to ensure that all the nooks and crannies are thoroughly cleaned.

Follow the steps below to perform a deep clean:

  • Step 1: Unplug your dishwasher. Press any button to make sure that there is no residual power left.
  • Step 2: Remove any removable components inside the dishwasher such as the basket, racks, and spray arms.
  • Step 3: Clean all the items thoroughly in warm water using a soft brush or damp cloth.
  • Step 4: Wipe the interior walls and the dishwasher base with a damp cloth soaked in white vinegar. Clean any excess detergent or cleaning agent left in the tub.
  • Step 5: Use a damp cloth or a cotton bud to scrape off any dirt build-up in the rubber door seals.

Next, take out the filter assembly to clean it. Follow the steps below if your model has a removable filter system:

  • Step 1: Unplug your dishwasher.
  • Step 2: Remove the lower rack to access the filter assembly.
  • Step 3: Rotate the filter handle counterclockwise to loosen the compartment door.
  • Step 4: Take out the compartment door and pull out the filter assembly underneath.
  • Step 5: Clean the filter and filter door, remove food remains, and soak them in distilled white vinegar overnight. Rinse them in running water.
  • Step 6: Reinstall the filter and fasten the filter door in place.

Simply follow the suggestions above and you will have your top rack dishes squeaky clean in no time.

However, if some of the steps are a little too complicated for you, call your dishwasher’s Support Center or ask a professional for help.

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