Clean and Maintain a Dishwasher

Most of us don't think about cleaning the dishwasher very often. After all, if the dishes are getting cleaner, shouldn't the dishwasher get cleaner, too? Unfortunately, debris and deposits do build up over time, and some of them reduce the performance of the dishwasher. If it's high time to clean yours, see Step 1 below to get started.

Steps

Doing a Deep Cleaning

  1. Fill the sink half full of water and add 2 cups of vinegar. This is going to be where your dishwasher bits are soaking while you clean up around the walls and base. If you don't have vinegar, consider the following:
    • Lemonade drink mix or lemon-flavored Kool-Aid mix. (Don't use strong colors that might stain. There is no need to add the sugar.)
    • Lemon juice
    • A dishwasher cleaning product [1]
  2. Remove the holders and racks. The two "shelves" of the dishwasher should be removed, along with the utensil holder and any other pieces that aren't a part of the racks. If they're small, place them into your vinegar-water sink for cleaning. If they don't fit, wipe them down with a rag damp with the same vinegar solution.
    • Check for food bits! If any are stuck on, use a toothpick or similar small, sharp tool to pry away at what's been caked on.
  3. Clear any debris out of the holes in spinning arms. Look to make sure all the holes are open so that water can run through them freely. If you have this problem, those holes will need to cleaned in order for your dishwasher to run efficiently. Use fine pointed or needle-nose pliers if you have some; otherwise, try a toothpick or something similar. Take care not to scratch anything if you're using a tool with a metal point. Remember to take your time and be careful.
    • If these holes are very small, bend a fine wire with a tiny hook on one end. Thread the wire through the opening most distal from the center of the arm. Each time you do this a small amount of debris will come out.
    • Another option is to drill a much larger hole at the end of the arm. Run the washer to eject the matter, then plug the bigger hole with a stainless steel screw.
  4. Wipe around the edges of the door and around the gasket. This space doesn't get washed during the dishwasher cycle. Use a damp cloth and the vinegar solution (or, if you like, a bit of mild spray cleaner). An old toothbrush or other soft, household brush can help get into corners and up under the gasket, too.
    • Don't forget under the bottom of the door! In some dishwashers, this is a dead spot where water doesn't go, so it can accumulate debris. Wipe this off with your vinegar rag. If anything is caked on, bust out your scrub brush as necessary.
  5. Remove mildew or mold with bleach. Run a separate cycle from any acid cleaners you have used and never mix bleach with other cleaners or with dishwasher detergent. Bleach is a very strong chemical, both on you and on your dishwasher, so use it sparingly and only when necessary.
    • If mold and mildew is a problem, leave the dishwasher loosely open for a while after each cycle to allow it to dry out.
    • Avoid using bleach and detergents containing bleach if your dishwasher has a stainless steel interior or door.
  6. Tackle rust stains. If your water has a lot of iron or rust in it, rust may be beyond your control. If possible, address the problem at its source. If the problem isn't rusty pipes, water softeners can remove a limited amount of iron from water but they mostly work by exchanging minerals that are hard to clean off surfaces for salts that are relatively easy to clean. Filters do exist to remove iron from water and might be worth looking into if your water is extremely high in iron.
    • Use a dishwasher-safe rust remover for the stains themselves, but seek out a professional to ask how they got there in the first place.[1]
    • If the finish is chipping or flaking off the wire baskets in your dishwasher, try a paint-on sealant made just for dishwasher racks. Pull out the racks and check the bottoms, too. If the damage is severe or widespread (not just a few tines but all of them), see if you can replace the entire rack. Online stores sell a wide variety of appliance parts, so your replacement part may be very easy to find.
  7. Replace all parts back into your dishwasher. Once the grate, filter, arms, and all the insides have been given their thorough cleaning and the smaller parts have had a chance to soak, place them back in as normal. Or proceed to the next section -- if your dishwasher is really bad, you can take apart the bottom and really get down to business.

Taking Apart the Floor of Your Dishwasher

Inspect the bottom of your dishwasher around the drain. There will be a grate or grill around it, under the arm. This is where wastewater goes. Look for debris clogging up this area. Remove any solid matter that builds up, especially bits of paper, shards of broken dishes, gravel, etc. If you think stuff has gotten down inside, you'll have to do some simple disassembly to get at it.

  1. To remove accumulated debris, unplug the dishwasher. Look for a plug under your sink. Make sure to unplug the dishwasher and not the garbage disposal! Follow the cord back to your dishwasher to make sure.
    • If your dishwasher is at all mobile, move it around to see the proper cord move.
    • Turn off the circuit breaker to be completely sure.
    • Look out for the heating element in the bottom, if it is still hot you will get a bad burn.
  2. Carefully remove the screws at the bottom. Take care not to drop them! The cover of the filter will lift off, leaving the area exposed.
    • As you disassemble this section, take care to notice what you take off and where. Take photos along the way and set the pieces someplace safe, in the order they came off. When you start reassembly, there will be no question of what you should do.
  3. Place a rag or a piece of tape on the opening of the filter. This is to prevent debris from getting in it as you clean it. You want the debris out of the dishwasher completely -- not clogging up the pipes even further.
  4. Use a cloth to remove solid debris and then scrub down the base as necessary. Be careful of handling broken glass if that is part of what you find here. Rubber gloves are a good idea, too.
    • Use a brush or a cloth to loosen and remove deposits. For dishwashers that have not been properly cleaned recently, you'll need a strong cleaning agent to get at the years of buildup.
    • Never use steel wool with soap, it embeds minute particles of iron and you will never make the rust go away.
  5. Screw everything back together and plug it back in. It'll be easiest to do the reverse of what you did to get it apart. Don't over-tighten the screws, especially if they are going into soft plastic.
    • You may want to give it a quick run to see if everything works like it should.

Mastering Routine Maintenance

  1. Use your dishwasher regularly. It will help to prevent food and other debris from building up in there, reducing the need to clean it. Occasionally run it empty, too -- on the short, water-saving cycle, of course!
  2. Run a bit of hot water in your sink before running the dishwasher. You will get cleaner dishes if the water starts hot. You can collect the water you run and use it for watering plants or other purposes. Run the water until what comes out of the tap feels hot.
    • Set the thermostat on your water heater to 120F (50C) [2]. Water that is cooler than this won't be very effective for cleaning. Water that is hotter than this may scald people.
  3. Run the garbage disposal before starting the dishwasher. The dishwasher drains into the same pipe as your sink, so that drain must be clear. If you're experiencing problems with your dishwasher, it may actually be stemming from your garbage disposal. Here are some applicable reads:
  4. Periodically run the dishwasher with vinegar. Place 2 cups of vinegar in the bottom of your dishwasher and run it on low, or the energy-saving setting. Halfway through, stop the dishwasher and let the vinegar soak on the bottom for 15 or 20 minutes.
    • After the time is up, turn it back on to finish. If it's really bad, you can let it soak overnight.
    • If smell is an issue, sprinkle 1/2 - 1 cup of baking soda around the bottom and run the washer as normal.[3]
  5. Spray the front of your dishwasher with a mild spray cleaner. Wipe it down with a sponge or soft cloth. Pay particular attention to the controls and the handle. Also, don't miss the little ledge between panels; they tend to collect dirt.
  6. Refill your dishwasher's rinse aid dispenser about once per month. Rinse aid helps to prevent spots on your dishes. Unscrew the round knob in the dishwasher door and pour in rinse aid according to package directions or your dishwasher's manual.
    • Don't use rinse aid if you have a water softener.[4]
    • Solid rinse aids are available. If you forget to refill liquid rinse aid, the solid ones are more visible, so they may help you remember.
    • If you prefer, some dishwasher detergents now have built-in rinse aid.


Tips

  • Run full loads to conserve water and energy, but don't pack dishes too tightly. Dishwashers wash dishes by spraying water over them, so the water needs to be able to get to the dishes to clean them.
  • Wear gloves if you prefer not to touch the cleaner or the debris.
  • Tang and Borax are useful cleaning agents, too.
  • Load your dishwasher properly, stacking items facing downward and inwards. Check that all the arms can spin freely before running the dishwasher.
  • Always promptly pick up any objects that fall to the bottom of the dishwasher.
  • Wash small items in the basket with your forks and knives so they don't slip through the racks and end up in the bottom. Some dishwashers even have enclosed baskets just for small items.
  • Don't wash containers with labels that could come loose. Scrape heavy debris and large particles off dishes before placing them in the dishwasher.
  • Not all dishwasher detergents work the same. The next time you buy a new container of detergent, try a different brand and see if you get better results. Look for ratings and reviews, too. At the very least, favor powders and tablets over gels and liquids, and keep them dry and free of excess moisture prior to use.
  • For dried-on gunk, get the area wet or spray the cleaner, then let it sit and dissolve for a few minutes before wiping. You'll save yourself a lot of scraping and scrubbing.
  • Don't pre-rinse too much. Dishwashers and detergents have both improved. If you haven't tried putting dishes in dirty lately, try it again. You may be pleasantly surprised.

Warnings

  • Never mix household cleaners, especially bleach, with other cleaners or chemicals.
  • If you're not comfortable doing some simple disassembly and reassembly, don't unscrew the stuff in the bottom of the dishwasher. It doesn't need frequent cleaning.
  • Use only detergents designed for use in dishwashers, not the liquid dish soap (washing up liquid) that you use to wash dishes by hand. The dishwasher is designed to contain water spraying from certain directions, not a thick layer of suds. You'll only make a mess.

Things You'll Need

  • 2 cups vinegar or acidic drink mix
  • A rag or sponge
  • A mild spray cleaner
  • A screwdriver

Related Articles

  • Repair Your Dishwasher’s Door Latch
  • Make Rinse Agent for Dishwashers

Sources and Citations