Why Your Dishwasher Isn’t Washing the Top Rack


Running a dishwasher cycle only to find that the plates, cups, and bowls in the top rack haven’t been cleaned at all can be a bit frustrating. It will most likely leave you wondering what’s wrong with your dishwasher – and if it can be fixed, or if you’re doomed to wash your dishes by hand.

That your top rack isn’t being cleaned is, without a doubt, an indication that something is wrong. How severe the issue is will differ quite a lot depending on the cause.

Before you resort to contacting a certified technician or repairman, you should have a look at these possible causes and DIY fixes. You may find a solution to get your dishwasher back to cleaning your dishes.

If your dishwasher isn’t washing the top rack, it may be because of the following reasons;

  • Low water pressure caused by too many appliances running at the same time or a curling dishwasher hose.
  • Obstructed upper spray arm caused by inproper loading of the dishwasher.
  • Broken sprayer arm seal
  • Clogging under the rack propeller jets caused by leftover food.
  • Dirty dishwasher
  • Clogged sprayer arm
  • Faulty circulation pump

You will first need to unplug your dishwasher to avoid being electrocuted.

This article will go over several possible reasons why your dishes in the top rack are not being cleaned well and what you can do about it.

Sounds interesting? Read on to learn more.

1. Low water pressure

This is the most common reason why your dishwasher is not washing the top rack. For water to be forced through the bottom sprayer arm and up through the top sprayer arm, there needs to be adequate water pressure.

Low water pressure makes it hard for the water to be sprayed with sufficient force to distribute the washing detergent and spray the food particles and other build-ups off of your dishes that are on the top rack.

If the pressure of the water coming out of your top sprayer arm is low, it will most likely not wash the dishes on your top rack adequately.

It is vital to note that there are several reasons why your water pressure might be low. It could be that you have too many appliances using water simultaneously, that your main water supply has problems supplying water, that the water inlet in the dishwasher is blocked, and other things.

Dishwashers actually require very little water pressure in order to do their job, but even so, running multiple appliances at once can lead to a shortage.

For instance, if you are using your dishwasher, shower, and tub simultaneously, the water pressure will be affected.

Solutions

Start by conducting a test to hinder yourself from making large investments in time and resources only to find out that the problem could be solved by minor adjustments.

1. Run one appliance at a time

Consider running only your dishwasher and see if it cleans properly and works as intended. If it does, then the water pressure is too low when the dishwasher and other appliances are used simultaneously.

In that case, you can fix it by reducing the number of appliances that are being supplied with water at one single time or increasing the total capacity by installing a pump.

2. Check the water delivery tube

The water delivery tube supplies the spray arms with water. If the tube has a blockage, it won’t be able to deliver the required amount of water to the spray arm. Check if the delivery tube has a filter, and if it does, remove any debris the filter has caught.

3. Twisting dishwasher hose

If your dishwasher hose starts to twist or curl somewhere between the dishwasher and the sink, the amount of water the hose can funnel will be limited significantly. Look underneath your sink and undo any kinks you may find.

4. Install a pump

Installing a pump between your main water supply and dishwasher will increase the water pressure. Pumps that are otherwise used for rainwater-sustained homes are great for this. They provide sufficient pressure to run home appliances and shut off automatically when no water is being used.

These pumps are quite inexpensive and will aid you with other devices that also require water pressure.

2. Obstructed upper spray arm

An obstructed upper spray arm can also be the reason why your dishwasher is not washing the top rack.

For instance, the tall items in the bottom rack can block the spray arm from rotating as it should be. As such, the water coming out of your spray arm will not reach your top rack dishes.

Solutions

1. Make sure the upper spray arm isn’t blocked

The best way to fix this issue is to ensure that the upper spray arm is freely spinning whenever you load your dishwasher with tall dishes. If it is blocked, consider moving the tall dishes or hand-washing them instead.

3. Broken sprayer arm seal

Another reason why your top rack dishes aren’t cleaned properly could be due to a broken sprayer arm seal. The sprayer arm is made of two sealed parts to force water up and clean your dishes.

If the sprayer arm seal is broken, water will leak out around the seal instead of it being forced up to wash your top rack dishes.

Solutions

Replace the seal

Replacing the damaged seal by yourself or getting an experienced technician to replace the dishwasher’s seal is your best bet. Doing it yourself is not overly complicated and it’s rather inexpensive.

  • 1. Remove the upper rack: Start by removing the dishwasher’s top rack. This is done by either opening or removing the stop clips that you can find on both sides of the rack – on the rolling tracks.
  • 2. Remove the tube from the spray arm: Flip the removed upper rack upside down. The spray arm and tube should be mounted on the underside of the rack. You should be able to find a screw in the middle of the spray arm. Unscrewing it will allow you to detach the tube from the spray arm. Do so.
  • 3. Remove the arm: Now that the tube has been detached you can also remove the spray arm from the rack.
  • 4. Remove the old seal from the spray arm and replace it with a brand new one. Once attached, put the spray arm and tube back onto the rack and mount the rack back in the dishwasher.

5. Dirty dishwasher

Having a dirty washer could yet be another reason why your dishwasher is not washing the top rack. For instance, if the dishwasher is dirty, there will be a build-up in the sprayer or the filter.

Therefore, your dishwasher needs to be cleaned at least once every month as a routine clean.

The dishwasher cleaning entails wiping it out, cleaning or changing the filter, and ensuring there are no clogs that could cause problems.

You also need to perform deep dishwasher cleaning every few months to ensure that the dishwasher is clean and won’t cause issues.

Routine cleaning enables you to prevent many problems, such as your dishwasher not washing the top rack. It also assists you in ensuring that the filter is going to work well and last longer.

You can also buy cleaners that can be used in your dishwasher to assist break down any build-up that might cause your dishwasher not to wash the top rack.

Want to learn more about proper cleaning routines for dishwashers? Click here.

6. Clogged Rack Propeller Jets (On the Spray Arm)

Another possible cause of your dishwasher not washing the top rack could be that the rack propeller jets are clogged.

The high-pressure jets on the spinning propeller inside the dishwasher must be in great condition to get the most out of your unit. If they’re damaged or clogged your dishwasher’s performance will be reduced significantly.

The jets send concentrated rays of water and detergent at the dirty dishes in the dishwasher through multiple small holes. While the water bursts out through multiple heads, clogging one or two holes is enough to notice a difference in water flow.

Clogging can happen quite easily because the dishwasher uses hard water. The mineral build-up that hard water leads to will eventually cause clogging in various areas. The propeller jets are one of those areas.

Food and detergent residue can also lead to clogged jets.

Solution

  • 1. Identify clogging: Look for the sprayer arm inside the dishwasher. Inspect the spinning propeller to see if any of the holes seem clogged or if water flow is restricted.
  • 2. Clean propeller jets: If you identify mineral build-up or residue in the propeller jet holes, remove as much as you possibly can.
  • 3. Reassemble the unit: Put all parts back together and run the dishwasher to see if it cleans the top rack as intended now.

7. Faulty circulation pump

A faulty circulation can also be why your dishwasher is not washing the top rack.

If you hear water filling up your dishwasher but not spraying within the first 30 seconds, it is most probably because the circulation motor is faulty.

It is vital to note that circulation pumps are responsible for getting the water all the way to the top sprayer arm. Whenever they fail to work, dishwashers will not wash the top rack.

You also need to note that the circulation pumps can be clogged, thus blocking the water from getting to the top sprayer arms, and this will result in your dishwasher not washing the top rack.

If clogs are present in your circulation pump, you need to dislodge them using a pipe cleaner or other suitable tool.

If your circulation pump is getting power and no clogs are visible, then it’s most likely the pump motor that has malfunctioned. If that’s the case, you will have to replace either the motor or circulation pump.

Clogged Chopper Blade

The dishwasher’s chopper blades are intended to handle the leftover food that has stuck to the loaded dishes. The blades pulverize the food once it has been sprayed off the dirty dishes during the dishwasher cycle.

The pulverized particles are then caught by the filter. Some dishwashers have self-cleaning filters which require no maintenance at all, while other dishwashers require you to clean the filter manually on a monthly basis.

The filter can be found at the bottom of the dishwasher’s cavity and can be accessed easily without using tools. You should be able to detach the filter by twisting it. Once removed, clean the filter thoroughly with a brush and soap.

With the filter removed and cleaned, proceed to check the inside of the food chopper to see if any washed off food has collected there. Be very careful when handling the chopper to avoid injuring yourself on the blades.

Final Thoughts

If your dishwasher is not washing the dishes in the top rack, then there is something wrong with your dishwasher.

Some of the reasons include low water pressure, an obstructed upper spray arm, broken sprayer arm seal, clogging under the rack propeller jets, dirty dishwasher, and faulty circulation pump.

You can fix these issues by following the listed guide above. If you follow the recommendations in this article, your dishes in the top rack should be clean in no time.

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Robin

Robin is in his 30s and still enjoys the things he enjoyed as a teenager. He has studied nutrition, personal training, coaching, and cooking. He has an ever-growing interest in the art of cooking the best burger in the world. Thankfully, he also loves going to the gym.

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