Knowing how to clean a dishwasher properly will improve its performance and protect your family’s health.
Even though they’re regularly filled with hot, soapy water, dishwashers can still harbor all sorts of buildup. In fact, that very warm, damp environment can promote the growth of various fungi which can cause breathing problems and skin infections.
How To Clean A Dishwasher
Yes, some tutorials say you can put a cup of vinegar in the top rack and run it. If the wash cycle were sufficient to kill fungi and mold in your dishwasher, you could simply set your machine on “sani rinse” and be done with it. It’s not, so don’t cut corners.
A dirty dishwasher can’t really be expected to get your dishes clean and your glasses odor-free. Fortunately, it only takes 15 minutes to clean the areas where bacteria, mold, and scale are likely to build up. Just be sure to start with an empty dishwasher so you can reach all of the surfaces you need to clean.
1: Inspect and clean the racks.
Peeling plastic and rusting rack tines can leave your dishes stained and scratched. If yours are looking beat up, try using a paint-on plastic sealant specifically for dishwashers (Plasti Dip is one) or visit your dishwasher manufacturer’s website to find replacement racks.
Be sure to examine the tracks and wheels on your racks, along with the cutlery holder, for food buildup or mold. Wash if needed and spray well with 3% hydrogen peroxide to kill mold spores.
2. Check the spinning arms.
Most modern dishwashers have a spinning arm on the bottom of the top rack, and another in the base of the dishwasher itself. Look in the holes on the spinner arms to make sure there’s no debris or crusted food in there. If you discover the holes are blocked you’ll need to remove the arm and scrub the holes to dislodge the buildup.
Likewise, if the spinner arms aren’t moving freely you’ll need to remove them and scrub away and mineral buildup or food residue that’s collected where they attach to the dishwasher.
3. Clean the filters.
Your dishwasher has two filters: an upper and a lower one. The upper filter is directly beneath the bottom spray arm and can be removed by gently turning it counter-clockwise. If you’ve never cleaned this filter before, be prepared to be disgusted: this is where soap scum, greasy residue, and mildew like to hide. Clean it by washing in hot, soapy water and scrubbing with a soft toothbrush if needed.
The lower filter is the screen-like mesh on the bottom of your dishwasher. Remove any food particles you find there, and give the screen a quick scrub. Be careful if you’ve ever broken or chipped a glass in the dishwasher, because this is where the shards will be.
4. Clean the rubber gasket and door.
The rubber gasket prevents water from spewing out of your machine when it runs. That means it’s constantly hit with water and often gets coated with mineral build-up and caked-on food. Scrub it with hot, soapy water and an old toothbrush, taking care to get between the folds. Open your door fully to do this and, while you’re at it, wash the bottom inside of the door. You’ll often find quite a bit of mold has built up there, too.
5. NOW you can run it with that cup of vinegar.
Since you’ve actually removed the mold, mildew, and fungi it’s now safe to follow that shortcut most dishwasher-cleaning tutorials recommend. Return the racks to the machine and start the longest, hottest cycle your dishwasher has. Let the machine run a minute then pause it and pour 1 cup of white vinegar into the bottom of your machine where it will get sloshed around and remove buildup as the cycle runs. (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.)
Tips to keep your dishwasher clean:
• Most commercial dishwasher detergents are formulated to clean better if you don’t completely 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.
• Leave your dishwasher slightly ajar when not in use so air can circulate and reduce mold buildup.
• Clean your dishwasher using the above steps at least once a season.
Need a reminder about chores like this? Subscribe to my free weekly newsletter for cleaning schedules, menu plans, and more!