Why is My Dishwasher Not Cleaning Dishes?

When was the last time you washed a day’s worth of dishes by hand?

Most of us are so used to the convenience of having a dishwasher at home, we tend to take it for granted. Handwashing dishes is time-consuming, uses a lot of water, and is not the most pleasant household task. Compared with our grandmothers and their forebears, we are spoiled in terms of this household chore being taken out of our hands by modern technology.

But what about if your dishwasher is not properly cleaning your dishes?

Dishwasher TabletReasons why Your Dishwasher may not be Working

  • If the interior of your dishwasher is dirty, it won’t be able to do its job. Food debris, grit, grease, soap scum, and mineral deposits can all compromise the cleanliness of your dishwasher.


  • A dirty filter may be the culprit. Newer, quieter dishwasher models have a removable filter which can be cleaned regularly (it is usually located below the bottom rack in the floor of the machine). Older models (which are louder) have a self-cleaning, non-removable filter.


  • Improper loading of dishes can prevent all of them from being accessed properly by the spray arms. This can also block the required movement of the sprayers.


  • Low water temperature or pressure may be the reason your dishes are not cleaning properly. Most dishwashers require consistent pressure and water temperatures of around 49 degrees C to work effectively.


  • The spray arms spin above and/or below the racks, spraying clean water on the dishes. A clogged spray arm will result in reduced water pressure.


  • A broken soap dispenser (often due to a stuck spring) may compromise detergent from reaching the dishes or release it at the wrong time in the washing cycle. Improper loading can also prevent the soap dispenser from opening.


  • Inlet valve failure will prevent water from flowing into the dishwasher properly. A hammering sound is a sign of this.


  • Inappropriate or low-quality detergent, using too much detergent, and failure to use a final rinse product can result in spotty dishes.

Quick Troubleshooting:

  1. Dish washing powder won’t dissolve – this could be due to inlet valve malfunction, circulation valve failure, low water temperature, blocked/stuck dispenser door, or a clogged spray arm.


  1. Top rack not cleaning – you may have an issue with dirty spray arms, or incorrect or over-packing on the bottom shelf may be impeding water access to the top shelf. Alternatively, it may be due to low water pressure


  1. Bottom rack not cleaning – low water temperature or pressure, clogged or stuck spray arms, over packing, or hard water.


Clean DishwasherTips for Improving Dishwasher Performance

  1. Run your dishwasher when it is full – they work better when evenly filled.
  2. Use the correct setting. Be guided by your manual.
  3. Don’t pre-rinse – dishwashers are designed to work best on items that have not been rinsed, beyond scraping off large bits of food residue.
  4. Try a new detergent. Use the right kind to suit the load – glasses, pots and pans, etc. Also, be mindful that detergent does have an expiry date and the enzymes which do all the hard work in the wash will die.
  5. Don’t use too much or too little detergent. The best solution to get it “just right” is to use dishwasher tablets/pods for the perfect amount.
  6. Use Rinse Aid (or tablets with rinse aid). Rinse Aid prevents water spots or a water film, but using too much can leave streaks.
  7. Load your dishwasher properly. Keep small plates closer to the spray arms and tall ones further away. Tall dishes and large items can shadow smaller ones and prevent water access. This results in an uneven clean. Be extra mindful of how you pack bowls and dishes – don’t stack them too close together.
  8. Make sure nothing blocks the spray arms from moving properly.
  9. Check the soap dispenser and that the hinge is working.
  10. Clean your dishwasher!
  11. Check water pressure, hoses, inlets, and pump.

 How to Clean your Dishwasher

  1. Remove the racks and scrub them.
  2. Remove and clean the filter.
  3. Check the sprayer arms and remove them carefully if they are removable. Scrub away any debris with an old toothbrush.
  4. Replace all components and run the empty dishwasher through a normal cycle. In place of detergent, use 2-3 cups of white vinegar and/or lemon juice (NOT bleach!) in the bottom of your dishwasher. This will remove scale and residue buildup and leave it sparkling clean and fresh.
  5. Gently wipe down the door seals with a soft cloth dipped in white vinegar.

There are several reasons why your dishwasher might not be performing properly. Whatever the cause, you’ll want to get to the bottom of it fast and get it fixed as soon as possible – because nobody has time for this appliance to not be working!

If all of the above steps have not addressed the problem, call a professional appliance service provider or the manufacturer for a professional service and diagnosis of the problem.