How to Fix a Dishwasher Not Cleaning Properly

November 6, 2023
Dishwasher Repair

It’s frustrating, but it happens – you go to unload your dishwasher and put away your sparkling clean dishes, only to find they have a residue of food particles on them! Perhaps it’s only the most heavily soiled items that are still dirty, or maybe everything is covered in a fine layer of filth. Either way, it’s not good! In this article, we look at the most common reasons a dishwasher might not be cleaning properly and how to fix it. 

Wrong Cycle 

This might sound simple, but don’t discount that your dishwasher might be on the wrong cycle settings! If you or someone in your household accidentally adjusted it to wash on a cold or delicate cycle, it could mean it can’t clean your dishes sufficiently. 

Ensure that it’s set to a regular wash cycle or a heavy-duty cycle, depending on how dirty your dishes are, and ensure it’s being washed at a temperature of around 130-140°F.

Wrong Detergent

Using the right detergent can make a big difference in how well your dishwasher cleans! It can particularly make a difference if you live in an area with hard water (water that contains a lot of minerals). Hard water makes it more difficult for detergent to form a lather, meaning it can’t clean your dishes as efficiently. 

Check your dishwasher users’ manual to see what detergent they recommend for your particular machine, and if you do have hard water in your area, do some research into what hard water detergents are recommended for your machine. 

Blocked Filters

Everyone knows you should clean out your dishwasher filter regularly, but how often is that? It might surprise you to know that some recommendations suggest cleaning out the filter as often as once a week, particularly if you don’t rinse your dishes before loading your dishwasher.

If your dishwasher has stopped cleaning correctly, a blocked filter could definitely be the culprit, so make sure you clean it out to see if that fixes the issue. To clean it:

  • Locate the dishwasher filter. This is located at the bottom of the dishwasher towards the front in most makes and models. 
  • Remove the filter by unscrewing it.
  • Use running water and a brush to scrub the filter clean. If it’s particularly dirty, soak it in warm, soapy water for ten minutes before cleaning. 
  • Replace the filter in the dishwasher and run another cleaning cycle to see if the dishwasher is now cleaning properly.

We recommend you read your dishwasher users’ manual to find the recommendations on how often you should be cleaning out your filter, and then do your best to stick to those recommendations going forward.


Overloading is another cause of a dishwasher not cleaning properly that is easy to fix! If you’ve recently acquired a new roommate and have noticed that the extra dishes coincide with your dishwasher not cleaning properly, it might not be a coincidence!

When you load the dishwasher, ensure that there is space between all the dishes for water to circulate – if two dishes are tightly touching, there’s no way they can be properly cleaned. It’s better to put on smaller loads more frequently than rewashing a big load by hand because nothing is clean!

Blocked Spray Arms

In order to clean your dishes, the dishwasher circulates warm, soapy water throughout the interior using the spray arms. These rotate while spraying, ensuring that your dishes are evenly coated. They are also responsible for the cycle’s rinse phase, ensuring all the soapy water is rinsed off your dishes. 

If the spray arms get blocked, it can mean that the water doesn’t come out of the holes in the arms as effectively, or in some cases, at all. 

To fix this:

  • Remove the spray arms from your dishwasher. In most models, they simply unscrew. However, you might need to remove the racks to access them. 
  • Visually inspect the holes in the spray arms to see if they’re blocked. You can also try running water into them from a hose to see if water can exit all the holes. 
  • If you notice they’re blocked, use a toothpick or similar to poke the debris loose. 
  • If they are full of debris, soak the spray arms in a warm, soapy solution for a couple of hours to soften. Then, run water through the spray arm and use a toothpick to loosen debris from the holes until water runs freely through all of them. 
  • Once they’re clean, put them back into the dishwasher and run a test cycle to see if your dishwasher is cleaning the dishes properly.

Please note that spray arm blockages are usually caused by food particles, often things like corn kernels or lentils. Keeping the filter clean and ensuring you don’t wash dishes with large amounts of fibrous food stuck can help prevent future blockages. 

Draining Issues

When your dishwasher is draining correctly, it drains away the dirty water first and then rinses the dishes with clean water. If there is a drainage issue, the dishes may be rinsed with dirty water, meaning there will be a layer of grime on your dishes. An issue with the drain hose usually causes a drainage issue. To fix this:

  • Pull the dishwasher away from the wall to access the drainage hose. You may need to use a furniture dolly, as dishwashers are heavy. 
  • Disconnect your dishwasher from the power supply.
  • Inspect the drainage hose. If you see any visible kinks, straighten these out. This may be enough to get your dishwasher draining properly once more. 
  • If you can’t see any visible kinks, you’ll need to inspect the hose for blockages. With a towel and bucket on hand to deal with any residual water in the hose, disconnect the drain hose from the back of the dishwasher and remove it from the drain pipe.
  • Run water through the hose to see if there seems to be a blockage. If it’s blocked, use a length of wire to clear any clogs. 
  • Once the clogs are cleared, replace the drain hose and put the dishwasher back in place. 
  • Turn it on and run another cycle to see if your dishes will now be cleaned properly.

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