You probably think your washing machine is the cleanest thing in your house. It literally exists to wash things. Logic says the soap and hot water should keep the machine itself pristine, right? Honestly, that’s a total myth. If you’ve noticed a weird, damp-basement smell clinging to your "clean" towels, or if there’s a gray sludge hiding under the rubber seal of your front-loader, you’re dealing with a biofilm party. It's basically a layer of bacteria, undissolved detergent, and skin cells.
Cleaning it isn't just about the smell. It’s about maintenance. When people ask how can I clean my washing machine, they usually wait until the machine starts yelling at them with an "OE" error code or a stench that fills the laundry room. But by then, the internal heating element might be scaled over with calcium.
Why Your Machine Actually Gets Filthy
Most of us use way too much detergent. It’s an easy mistake. We think more bubbles equals more clean, but modern High-Efficiency (HE) machines use very little water. When you dump in a giant capful of Tide or Gain, the machine can't rinse it all away. This leftover soap creates a sticky film. Add in the body oils and lint from your clothes, and you’ve got the perfect breeding ground for Klebsiella pneumoniae or Staphylococcus aureus.
Microbiologist Charles Gerba, often nicknamed "Dr. Germ," has famously noted in various studies that fecal matter and bacteria frequently transfer between clothing items in the wash. If you aren't disinfecting the drum, you're just swirling that stuff around.
Then there's the temperature issue. We’ve all been told to wash in cold water to save the planet and our electric bills. While that’s great for your cotton tees, it’s terrible for the machine. Cold water doesn't kill bacteria, and it certainly doesn't melt away waxy fabric softeners. Softeners are essentially liquid fat. They coat the outer tub (the part you can't see) in a layer of gunk that smells like a floral swamp after a few months.
The Vinegar vs. Bleach Debate
Everyone has an opinion here. Some people swear by white vinegar because it’s "natural." Others won't use anything but straight chlorine bleach. Here is the nuance: they do different jobs.
Vinegar is an acetic acid. It’s fantastic for breaking down limescale and hard water deposits. If you live in a place with "hard" water (high mineral content), vinegar is your best friend. However, it’s not a registered disinfectant. It won't kill every type of mold or bacteria lurking in the deep recesses of the pump.
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Bleach, on the other hand, is the nuclear option for mold. If your gasket is black with mildew, vinegar won't touch it. You need the sodium hypochlorite in bleach to actually kill the spores. Never mix them. Seriously. Mixing vinegar and bleach creates chlorine gas, which is toxic. Pick a lane and stick to it for that specific cleaning cycle.
Dealing with the Front-Loader Gasket
Front-loading machines are notorious for this. That big gray rubber ring? It’s called the bellows. It has folds designed to allow the drum to move, but those folds trap water. If you don't wipe it out, it rots.
- Pull the rubber back.
- Use a microfiber cloth soaked in a 50/50 water and bleach solution.
- Wipe every single crevice.
- If you find a bobby pin or a stray coin, get it out of there before it tears the seal.
If the mold is really "baked in" to the rubber, you might need to soak some paper towels in bleach, stuff them into the folds of the gasket, and let them sit for three hours. This gives the chemicals time to penetrate the porous silicone.
How Can I Clean My Washing Machine Internally?
Most modern machines have a "Tub Clean" cycle. If yours doesn't, just use the hottest setting available—usually the "Sanitize" or "Whites" cycle.
For a standard deep clean, start with the dispenser drawer. Most people don't realize that whole drawer usually pops right out. Press the little release lever (usually in the middle of the softener compartment) and pull. You’ll probably find a thick, black sludge underneath it. Scrub that in the sink with an old toothbrush and some dish soap. Dry it completely before putting it back.
Once the drawer is clean, move to the drum.
Dump two cups of white vinegar directly into the drum and run a hot cycle. The acidity will strip away the "scrud"—that’s the technical-ish term for the waxy buildup of soap and skin cells.
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After that cycle finishes, do a second round. This time, use a dedicated washing machine cleaner like Affresh or OxiClean Washing Machine Cleaner. These contain sodium percarbonate (oxygen bleach), which is much more effective at breaking down the organic biofilms than just liquid bleach alone. It fizzes and foams, reaching the parts of the outer tub that the water level doesn't usually hit.
The Forgotten Filter
This is the part everyone ignores until the machine stops draining. Most front-loaders have a small door at the bottom front. Behind it is a drain pump filter.
Fair warning: When you unscrew this, water is going to gush out. Have a shallow tray and some towels ready.
This filter catches everything: hair, coins, Lego pieces, and a truly disgusting amount of gray slime. If you’ve been wondering why your machine smells like a sewer, this is usually the culprit. Unscrew it, rinse it under the tap, and check the hole for any obstructions. Screw it back in tight. If you don't tighten it properly, you'll have a flood the next time you run a load.
Top-loaders often don't have this accessible filter, but they do have a lint trap—sometimes on the side of the drum or inside the agitator. Check your manual. If your clothes come out with white flakes on them, your lint trap is full.
Maintenance Habits That Save You Money
You shouldn't have to do a "deep clean" every week. If you change how you do laundry, the machine stays cleaner longer.
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- Leave the door open. This is the #1 rule. If you close the door right after a load, you're sealing moisture into a dark, warm environment. That’s a literal incubator for mold. Leave the door ajar at least four inches.
- Switch to powder. This is controversial, but many appliance repair technicians, like those from the popular "Ben’s Appliances and Junk" channel, argue that high-quality powders (like Persil or certain HE-rated powders) are less likely to create the "scrud" buildup compared to liquid detergents which contain more fats and oils.
- Skip the fabric softener. Honestly, it’s not doing your clothes any favors, and it’s a nightmare for your machine's internals. Use wool dryer balls instead.
- Wipe the seal. Keep a rag on top of the machine. When the last load is done, give the rubber gasket a quick 5-second wipe.
Special Considerations for Top-Loaders
Top-loaders have a different set of problems. They don't usually get the gasket mold, but they do get "biofilm splash" above the water line. The top rim of the tub—the part that stays dry during a wash—collects a layer of dust and dried detergent.
Take a damp cloth and wipe around the top of the tub and the underside of the lid. You’d be surprised how much dust and grime accumulates there. If your machine has a center agitator, the top cap usually pops off. Check inside. If it’s filled with black gunk, soak it in hot water and vinegar.
For the actual cleaning cycle in a top-loader, let the machine fill with hot water, add your cleaning agent (vinegar or a tablet), and then pause the machine. Let it soak for an hour. This "soak time" allows the chemicals to dissolve the buildup on the agitator and the outer tub walls before the rinse cycle flushes it all away.
Actionable Next Steps
To get your machine back to factory-fresh status, do these three things today:
- Execute the "Purge" Cycle: Run a "Sanitize" or "Heavy Duty" cycle on the hottest water setting with two cups of white vinegar or a professional cleaner tablet. Do this with an empty drum.
- Manual Scrub: Pop out the detergent drawer and scrub the housing. Then, pull back the rubber gasket and wipe away any visible slime with a diluted bleach solution.
- The Filter Check: Locate your drain pump filter (usually at the bottom front) and clear it out. Have a towel ready for the "stink water."
From here on out, commit to leaving the door open after every wash. This simple habit reduces the need for deep cleaning by about 70%. If you notice the smell returning in a few weeks, it's a sign you’re using too much detergent—cut your usage in half and see if the suds disappear during the rinse cycle. Most people only need about two tablespoons of HE detergent for a standard load. Anything more is just feeding the mold.