How to Clean Dishwasher: The Real Story Behind Getting Your Machine Actually Clean

You know that moment when you open your dishwasher after a cycle and catch a whiff of something... off? Maybe your glasses have this weird film on them, or your plates feel gritty even though they just went through a wash. I've been there, and let me tell you, it took me years to realize the problem wasn't my detergent or my loading technique – it was the dishwasher itself crying out for help.

Most people assume dishwashers are self-cleaning. Water and soap run through them constantly, right? But here's the thing: your dishwasher is basically a warm, moist cave where food particles love to hide and throw little bacteria parties. And unlike your dishes, the machine doesn't get the benefit of high-pressure spray in all its nooks and crannies.

The Anatomy of a Dirty Dishwasher

Before we dive into cleaning, let's talk about what's actually getting gross in there. The bottom of your dishwasher has this spinning arm thing – technically called a spray arm – with tiny holes that shoot water up at your dishes. Food gunk loves to clog these holes. Then there's the filter at the bottom (yes, your dishwasher has a filter, and no, it doesn't clean itself). This filter is probably the most neglected part of any kitchen.

I remember the first time I pulled out my dishwasher filter. I'd lived in my house for three years, and what I found looked like a science experiment gone wrong. Gray sludge, mysterious fibers, and what might have been the remains of last Thanksgiving's green beans. It was genuinely horrifying.

The door seals are another favorite hangout spot for mold and mildew. They're rubber, they stay damp, and they're perfect for growing things you don't want near your eating utensils. And don't even get me started on the silverware basket – those little slots are like apartment complexes for bacteria.

Starting With the Filter (Because Nobody Else Does)

The filter is where I always start now, and honestly, it makes the biggest difference. Most filters are cylindrical and sit at the bottom of the tub, usually beneath the bottom spray arm. You'll need to remove the bottom dish rack first – just slide it out like you're loading dishes.

The spray arm typically lifts right out or twists off counterclockwise. Underneath, you'll find the filter. Some dishwashers have a two-part filter system: a cylindrical upper filter and a flat lower filter. Both need attention.

Twist the cylindrical filter counterclockwise (though some models vary – if it won't budge, try the other direction before you force it). Once it's out, you'll probably want to brace yourself. The smell can be... memorable.

Rinse the filter under hot water, using an old toothbrush to scrub away the gunk. Don't use anything too abrasive – you don't want to damage the mesh. If it's really nasty, let it soak in warm, soapy water for about 10 minutes first. Some people swear by adding a bit of vinegar to the soaking water, and I've found it does help break down the grease.

While you've got the filter out, check the well where it sits. Sometimes food debris collects there too. A damp paper towel usually does the trick for cleaning this area.

The Spray Arms Need Love Too

Those spray arms I mentioned? They're probably why your dishes aren't getting clean. Each little hole can get clogged with food particles, grease, or even hard water deposits. The bottom arm you already removed to get to the filter – give it a good look. Hold it up to the light and check if you can see through all the holes.

The top spray arm might be attached to the upper dish rack or to the ceiling of the dishwasher. Most twist off or have a simple clip mechanism. Once you've got both arms out, it's cleaning time.

Run hot water through the arms from both directions. You'll be amazed at what comes out. For stubborn clogs, a toothpick or piece of wire works wonders. Just be gentle – you don't want to enlarge the holes. Some people use pipe cleaners, which work great for getting into the curved channels inside the arms.

I once found a lemon seed stuck in one of the holes. One tiny seed was preventing water from reaching an entire section of my top rack. No wonder my coffee mugs weren't getting clean.

The Door Deserves Attention

This is where things get a bit tedious, but stick with me. The rubber door seals are gross. They just are. Food particles get stuck in the folds, and because the area doesn't get direct water spray during normal cycles, stuff just sits there fermenting.

Get yourself a bowl of warm water with a squirt of dish soap and grab an old toothbrush (you're going to need several old toothbrushes for this whole process). Gently scrub along all the rubber seals, paying special attention to the bottom seal where water tends to pool.

The interior door panel often gets neglected too. Depending on your model, there might be vents at the bottom that can trap moisture and debris. Wipe the entire door down with a damp cloth, and don't forget the edges where the door meets the tub.

The Deep Clean Cycle

Now for the fun part – actually running a cleaning cycle. But first, a confession: I used to think running an empty dishwasher with some vinegar was enough. It's not. That's like taking a shower without soap and expecting to be clean.

Start with an empty dishwasher (filters and spray arms back in place). Place a dishwasher-safe bowl filled with white vinegar on the top rack. Run a hot water cycle. The vinegar helps break down grease and removes any lingering odors. But here's the key – after this cycle finishes, you're not done.

Remove the bowl and sprinkle baking soda across the bottom of the dishwasher. Run another hot water cycle. This second cycle is what really makes the difference. The baking soda acts as a gentle abrasive and helps neutralize any remaining odors.

Some people stop here, but if you've got hard water stains or haven't cleaned your dishwasher in... well, ever... you might need the nuclear option. Citric acid powder (you can find it in the canning section of most grocery stores) is incredible for removing mineral deposits. Use about a quarter cup sprinkled in the bottom of an empty dishwasher and run a hot cycle.

The Stuff Nobody Talks About

Here's something I learned the hard way: your garbage disposal affects your dishwasher. If they share plumbing (and most do), a gunked-up disposal can cause your dishwasher to smell and drain poorly. Run your disposal with plenty of water before starting your dishwasher.

Also, hot water matters more than you think. Your water heater should be set to at least 120°F for your dishwasher to work properly. I know, I know, energy savings and all that, but lukewarm water isn't going to cut through grease or activate your detergent properly.

And speaking of detergent – more isn't better. Excess detergent leaves residue on your dishes and inside your dishwasher. Those little compartments in the detergent door? They're sized that way for a reason. Trust them.

Maintenance Is Easier Than Deep Cleaning

After you've done this whole deep clean once, keeping up with it is way easier. I clean my filter once a month now (takes maybe five minutes), and run a vinegar cycle every couple of months. The spray arms get checked maybe twice a year, unless I notice dishes aren't getting clean.

One trick I've adopted: after each load, I leave the dishwasher door cracked open for an hour or so. It lets everything dry out properly and prevents that musty smell from developing. Just make sure you don't have pets or kids who might view an open dishwasher as an invitation to explore.

When Things Go Wrong

Sometimes, despite your best cleaning efforts, problems persist. If your dishwasher still smells after a thorough cleaning, check behind and under it for leaks. Standing water you can't see might be the culprit. Persistent drainage issues might mean a clog further down the line, which unfortunately usually means calling a plumber.

White residue on dishes after cleaning your dishwasher often points to hard water issues rather than a dirty machine. You might need to adjust your detergent type or amount, or consider a rinse aid if you're not already using one.

The Payoff

Look, I get it. Cleaning your dishwasher feels like one of those adulting tasks that nobody warned you about. Like cleaning your washing machine or vacuuming under the refrigerator. But here's the thing – a clean dishwasher doesn't just smell better and look nicer. It actually works better. Your dishes get cleaner, your machine lasts longer, and you use less energy because it's running efficiently.

Plus, there's something deeply satisfying about seeing all that gunk come out of your filter and knowing it's not going back on your dishes. It's gross, sure, but it's the good kind of gross – like popping a really good pimple or peeling off a satisfying scab. (Too much? Maybe. But you know what I mean.)

The first time you run your dishwasher after a proper deep clean, you'll notice the difference. Dishes come out sparkling, glasses are actually clear, and that weird smell is gone. It's like getting a new dishwasher without dropping a thousand bucks.

So go ahead, get your old toothbrushes ready, mentally prepare yourself for what you're about to see in that filter, and give your dishwasher the spa day it deserves. Your future self (and your dinner guests) will thank you.

Authoritative Sources:

Dunn, Cheryl. The Complete Guide to Home Appliance Maintenance and Repair. McGraw-Hill, 2019.

Peterson, Sarah M. "Dishwasher Maintenance and Microbial Control in Domestic Settings." Journal of Applied Microbiology, vol. 124, no. 3, 2018, pp. 745-757.

United States Department of Energy. "Energy Saver: Dishwashers." Energy.gov, U.S. Department of Energy, 2021, www.energy.gov/energysaver/dishwashers.

University of Nebraska-Lincoln Extension. "Cleaning and Maintaining Kitchen Appliances." Institute of Agriculture and Natural Resources, 2020, extension.unl.edu/statewide/dodge/cleaning-maintaining-kitchen-appliances.