How To Deep Clean A Dishwasher

Clean

Your dishwasher probably contains hardened food particles, mineral buildup, greasy residue, and even mold. Time to deep clean it.

Woman kneeling next to open dishwasher and removing the filter to clean it

Even though they’re regularly filled with hot, soapy water, dishwashers collect all sorts of buildup. In fact, that warm, damp environment is ideal for mold and various dangerous fungi to grow. Taking the time to deep clean your dishwasher the right way helps it work better and eliminates things that could make your family sick.

Vinegar Alone Does Not Clean Dishwashers

You may have read that you can clean your dishwasher by putting a cup of vinegar on the top rack and running it. The idea is that the rinse cycle will splash the vinegar around and get your dishwasher clean. But if that’s all it took, you could also just run your machine’s sanitizing cycle and be done with it.

The fact is, there are spots in your dishwasher that require deeper cleaning. Places like your filters, gasket, and spinning arms need additional care. So, don’t cut corners if you want to do the job right. Fortunately, it only takes a few minutes of active effort on your part to deep clean your dishwasher inside and out.

How To Deep Clean Your Dishwasher

Time required: 15 minutes active effort, plus a full dishwashing cycle

Equipment You Will Need

  • Old toothbrush
  • Tweezers
  • Toothpick or pipe cleaner
  • Flashlight
  • Lint-free cleaning rags
  • Measuring cup

Materials You Will Need

  • 3% hydrogen peroxide
  • Liquid dish detergent
  • Distilled white vinegar
  • Pliers (in some cases)

Instructions

Interior view of racks, spinning arm, and filter in a clean dishwasher

1. Inspect the Racks

Inspect the tips of the tines on your racks. If their coating is nicked or peeling, they can leave rust on your dishes and scratch them. Visit your dishwasher manufacturer’s website for replacement racks. To fix them yourself, use a rubberized sealant that can handle the extreme heat in dishwashers. (I used Plasti-Dip* successfully on ours after a big roasting pan knicked the lower rack and led to rust problems.)

2. Clean the Racks

Carefully remove the racks and utensil holders from your dishwasher and give them a good scrub in a sink full of soapy water. Pay special attention to the tracks and wheels on your dishwasher rack. These collect a lot of grime that can keep them from sliding easily. Dip the toothbrush in white vinegar and scrub any hard mineral buildup you discover on the racks or utensil holder.

3. Check the Spinning Arms

Look in the holes on the spinner arms to make sure there’s no debris or crusted food in there. If you discover blocked holes, you’ll need to remove the arm and scrub them to dislodge the buildup. You may need pliers to do that. Once you’ve got the spinner off, use tweezers to pull out anything stuck in the holes. You can also insert a toothpick or pipe cleaner to dislodge mineral buildup.

Male hand removing filter to deep clean dishwasher

4. Scrub the Filters

Your dishwasher has two filters: an upper and a lower one.

  • The top filter is the round thing sticking up from the floor of your dishwasher. It’s removable, so turn it gently to the left to remove it. If you’ve never cleaned this filter before, prepare to be disgusted: this is where soap scum, greasy residue, and mildew hide. Let it soak for several minutes in a sink of hot, soapy water, then gently use an old toothbrush to remove grime. Rinse it well and let it air dry while you continue deep cleaning your dishwasher.
  • The lower filter is the screen on the floor of your dishwasher. This is not removable, so you’ll have to clean it in place. It’s not uncommon to find shards of glass or dishware here. So, before you begin cleaning, make sure there aren’t any that could cut you. (Use the flashlight so you can see to do this.) Once you’ve removed any broken glass, use the tweezers to pull out anything stuck in the mesh. Then scrub the whole thing with a cleaning rag dipped in vinegar to remove any grime. Use a toothbrush on stubborn spots.

5. Clean the Gasket and Door

Open your dishwasher door all the way and wipe it with warm, soapy water. While it’s fully open, clean the inside bottom edge — you’ll find a lot of residue growing there, so switch to a clean cloth as needed. Next, use your fingertips to pry open the folds of the rubber gasket gently. Clean between these folds with hot, soapy water and rinse with a damp cloth.

Do not use vinegar on the gasket — it can damage rubber and ruin the seal that keeps your dishwasher door water-tight. If you find mold or mildew, spray it with 3% hydrogen peroxide, not vinegar. Let the hydrogen peroxide air dry, then wipe the area with a clean, damp cloth to remove any residue.

6. Let the Machine Clean Itself

Now that you’ve deep cleaned your dishwasher’s various parts, put it back together and pour 1 cup of white vinegar on the bottom of your machine. Return the racks to the machine and select your machine’s longest, hottest cycle using the sanitizing setting or temperature boost and heat drying. Do not add detergent or dishes.

Let the machine run for a few minutes, so it drains any water collected inside. Then pop the door open to pause the cycle and pour 1 cup of white vinegar on the floor of the machine. (Alternatively, you can sprinkle in a packet of unsweetened Lemon Kool-Aid or powdered Tang — the citric acid in these products is excellent at removing mineral buildup.)

It’s not a bad idea to clean your garbage disposal when you’re done deep cleaning your dishwasher. The disposal uses the same drain, so keeping it free of grime and flowing well helps your dishwasher stay odor-free and clean, too.

How Often to Clean Your Dishwasher

Here’s how often to clean your dishwasher to keep it from smelling bad or developing mold.

Daily: Most commercial dishwasher detergents are formulated to clean better if you don’t rinse your dishes before loading them into the machine. You should still scrape away large bits of food, though, so they don’t collect in the upper filter.

Weekly: Wash the removable filter in hot, soapy water and let it air dry. Spray the door on both sides with an all-purpose cleaner and wipe away grime. (Here’s how to clean and polish stainless steel doors.)

Monthly: Wipe the gasket and bottom inner edge of the door. Inspect the racks for damage and repair as needed.

Seasonally (or more often): Follow the steps above to deep clean your dishwasher, and you’ll keep it in top working condition.

6 Comments

  1. Katie, you mention not to use bleach if the dishwasher has a stainless interior – what should I use instead to disinfect it? Thanks.

    1. Katie Berry says:

      Helen, I’d suggest filling a measuring cup with straight white vinegar and putting it on the top rack then run a cycle with only that in the machine. If mildew or discoloration are an issue, maybe give it a good scrubbing beforehand. Here’s my homemade soft scrub recipe — it’s safe for stainless steel and does a fantastic job!

  2. Elizabeth Ellis says:

    I am confused about the two filters. I clean the one under the metal scratches least weekly but don’t worry understand where the other one is. Do you have pictures of the two? Also. What is the round dome with holes on the bottom? My dishwasher is manually cleaned all the time but my glasses reek! Thanks for your help.

    1. Katie Berry says:

      Hi Elizabeth,
      That round dome is probably another filter. I’d suggest looking online for your dishwasher instruction manual if you don’t still have it. In my Whirlpool dishwasher, turning the dome gently counterclockwise releases a round filter with a fine screen that gets downright disgusting. Washing it in warm, soapy water with an old toothbrush eliminates a lot of odors and helps my dishwasher work much better. But be sure to check your manual to see if that dome is a filter or something else!

  3. Starr Harmoning says:

    Will you please talk more about cleaning the fromt of the dishwasher door? Mine is stainless, but something clearly dripped down the front and I cant seem to get it clean.

    1. Katie Berry says:

      Hi Starr,
      If it’s a gunky drip, try rubbing it with olive oil and letting that sit for a while. Oil dissolves the bonds that make greasy messes stick to metal, so you should then be able to rub it away. You might try using a wooden spoon or spatula to scrape the mess without damaging the stainless steel, too.

      For crusty drips, try a little Bar Keeper’s Friend on a damp sponge. The oxalic acid in BKF helps loosen a lot of grime without scratching stainless steel.

      Once it’s gone, wash the surface with warm, soapy water and rinse it well. Then buff it to a shine with a little more oil on a cloth.

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