Tips to Fix a Dishwasher That Leaves Dirty Dishes

Cleaning Dishwasher Filter

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When you purchased your dishwasher, you were likely excited at the prospect of having sparkling, clean dishes. But that excitement didn't last forever, and at some point the machine no longer performed like a winner.

You began to notice dishes were coming out with a slight residue or, worse, they were thickly coated with remaining food that had baked on during the dry cycle. Whether it happened slowly or overnight, your dishwasher is now leaving you with dirty or cloudy dishes.

Why Isn't Your Dishwasher Working Well?

This is actually more normal than you may think. Dishwashers work enormously hard, day in and day out. Your dishwasher may be past its prime and in need of replacement. Or it may require major repairs.

But, in some cases, the problem can be solved simply by switching dishwasher detergents or by cleaning the dishes less before running the cycle.

In other cases, you'll need to dig a little deeper into your dishwasher's inner workings. You can fix the problem by yourself—while leaving the machine in place—by using basic tools and a few materials.

Use the Right Dishwasher Detergent

Along with the mechanical action of the dishwasher, your dishwasher detergent is just as important at successfully removing food and cleaning your dishes.

Consult your machine's instruction manual for recommended detergents. If you have hard water, look for a detergent with added water softeners. Or, you can purchase a separate additive that boosts your machine's cleaning ability and reduces filminess.

Scrape Rather Than Rinse Dishes

It might seem counter-intuitive, but leaving more food on the plates actually helps your dishwasher perform better.

If you are in the habit of pre-rinsing your dishes, many experts recommend reconsidering this. You will always need to scrape off large particles but do not rinse off the dishes with water.

Detergents' enzymes need solid food particles to latch onto. Activated by the water, the enzymes quickly break down the food proteins into smaller and smaller particles, until the particles release from the dishes and wash away.

Clear the Spray Arms

Your machine has upper and lower spray arms that deliver water to your dishes. If those spray arms are clogged, even partially, their ability to deliver that water is greatly hampered. So, you'll need to remove the spray arms, clear them, and put them back in place.

  1. Turn off the electrical supply to the dishwasher at the service panel by turning off the breaker.
  2. Remove the dishwasher's lower rack and set it aside.
  3. All machines' spray arms have different removal methods. Consult your instruction manual for details.
  4. After the spray arms are free, thread a piece of thin, flexible wire (not a coat hanger!) into the holes on the spray arms to clear any mineral deposits or debris.
  5. If you wish to clean the spray arms further, soak them in white vinegar for about two hours.
  6. Replace the spray arms, turn on the electrical supply, and test the machine.

Clear and Clean the Filters

One benefit of removing your dishwasher's spray arms is that it permits access to the dishwasher's filters. Filters prevent dislodged food from being recirculated back over the dishes. They also prevent large food items and non-food debris from being sent down your sewer line.

Most dishwasher manufacturers recommend cleaning the filters at least once a year. If you do not scrape food before loading and you run over 10 loads per week, you may need to clean the filters as often as once a week.

Filtration systems differ with every dishwasher. Generally, there is a coarser filter for the large items and a fine, mesh filter for small food particles. Run the filters under warm water. Begin by holding the filters upside-down, so that the water can more easily dislodge the particles from the top of the filter. Then brush gently with a soft brush or sponge until it's clean. Then, replace it in the dishwasher.

Check and Adjust the Water Temperature

Water cleans dishes, but hot water cleans them even better. That is why a hot water wash cycle is so important to effectively clean your dishes.

Water that enters your dishwasher is already hot, having been heated from your home's water heater. The dishwasher then heats the water another 30 degrees Fahrenheit.

To ensure that water is at least 120 degrees Fahrenheit by the time it reaches the dishwasher, use a glass candy thermometer to check the temperature of the hot water leaving the kitchen faucet. Fill a glass and then place the thermometer in the glass until the indicator peaks. Here are more tips for adjusting water temperature:

  • If the temperature is below 120 degrees Fahrenheit, raise the temperature on the water heater.
  • Sometimes hot and cold supply lines get inadvertently switched. Check under the kitchen sink to see if the lines are hooked up correctly.
  • Let the hot water in your kitchen sink run for about two minutes before starting the dishwasher. This brings hot water to your destination so that it is ready to be used by the dishwasher. Otherwise, the dishwasher would begin pulling tepid or even cold water that has been sitting in the hot water supply line.