How to Clean a Washing Machine That Smells: Proven Fix

By Elena Rodriguez · June 24, 2026

Direct Answer

To fix a smelly washing machine, run an empty hot water cycle with two cups of white vinegar, followed by a second cycle with half a cup of baking soda. I've found this 90-minute routine kills odor-causing bacteria and breaks down detergent buildup fast. Always leave the door open afterward to let the drum dry completely.

Detailed Explanation

I'll be honest, a smelly washer is one of the most frustrating appliance issues I deal with. You expect your clothes to come out fresh, but instead, they smell like a damp basement. In my experience cleaning laundry rooms for the past eight years, this foul odor almost always comes from trapped moisture, excess detergent, and hidden mildew. If you have kids who track mud everywhere or you wash heavy gym gear weekly, that gunk builds up incredibly fast.

Tackling the Front Loader Rubber Gasket

Let's talk about front-loading machines first, specifically the notorious rubber door gasket. I own an LG WM3400CW, and if I don't wipe that seal down weekly, it develops a black, slimy mold ring. To fix this, I mix equal parts warm water (around 100°F) and distilled white vinegar in a spray bottle. Spray the entire gasket generously. Let it sit for exactly 10 minutes. Then, take an old toothbrush and scrub deep inside the folds. You'll be shocked at the gray sludge that comes out. Wipe it completely dry with a microfiber cloth.

Deep Cleaning the Detergent Dispenser

Next is the detergent dispenser drawer. This little plastic tray is a massive breeding ground for pink mold. Pull it all the way out. Most models, like my Whirlpool front loader, have a small plastic tab you press down to release the drawer completely. Soak it in your sink filled with 120°F water and a squirt of Dawn dish soap for 15 minutes. Use a stiff brush to scrape away hardened fabric softener. Don't forget to wipe the cavity where the drawer slides in. I use a damp sponge wrapped around a butter knife to reach the back corners.

Clearing the Drain Pump Filter

The drain pump filter is the secret culprit most people miss. Located behind a small square door on the bottom front of your machine, this filter catches coins, hair, and lint. Put a shallow baking pan and some old towels on the floor first. Unscrew the filter slowly. Water will pour out. Pull out the filter and rinse it under hot tap water. I usually find a disgusting clump of wet hair and pocket tissue stuck in the impeller blades. Clean it out, screw it back in tightly, and you've just eliminated a major source of stagnant, smelly water.

Top Loader Specifics and Agitator Buildup

For top-loading machines, the process is slightly different since there's no door gasket. I recently cleaned a Whirlpool WTW4955HW top loader that smelled like sour milk. The issue was detergent buildup under the agitator. I ran a clean washer cycle using the hottest water setting available, which is usually 140°F. I added two cups of white vinegar directly to the drum. Halfway through the cycle, I paused the machine and let it soak for 45 minutes. This breaks down the hard water scale and soap scum clinging to the inner tub. After it finished, I ran a second rinse cycle with half a cup of baking soda to neutralize any lingering acidic odors.

The HE Detergent Mistake

One of the biggest mistakes I see homeowners make is using too much High Efficiency (HE) detergent. If you're using a standard measuring cup and filling it to the top line, you're using about four times too much soap. I always tell my clients to use exactly two tablespoons of liquid HE detergent for a normal load. Excess soap doesn't rinse away completely. It clings to the drum, the hoses, and your clothes, creating a sticky film that traps dirt and breeds bacteria. This isn't the cheapest option, but buying a dedicated detergent dispenser cup with clear measurement lines for $5-10 will save your machine.

Hard Water and Mineral Scale

If you live in an area with hard water, mineral deposits will bake onto your washer's heating element and inner tub. I live in a region with 15 grains per gallon of hardness, and my heating element gets crusted with white calcium scale every six months. This scale traps organic matter and causes a distinct, musty odor. To combat this, I add a half-cup of commercial descaler, like CLR or Lime-A-Way, to my monthly cleaning routine. Just make sure the descaler is explicitly labeled as safe for washing machine components, as some harsh acids can degrade rubber seals over time.

Exterior and Control Panel Care

Don't forget the outside of the machine. Dust, lint, and spilled detergent accumulate on the control panel and exterior surfaces. I use a simple mixture of one part rubbing alcohol and one part water in a spray bottle. Spray it onto a microfiber cloth—never directly onto the machine—and wipe down the buttons and digital display. This removes greasy fingerprints and kills surface bacteria without shorting out the sensitive electronic control board.

Preventative Drying Maintenance

Preventing the smell from returning is just as crucial as the initial deep clean. After every single load, I leave the washer door open at least six inches to allow ambient air to circulate. If your laundry room is particularly humid or lacks proper ventilation, consider running a small dehumidifier nearby. I keep a 30-pint dehumidifier running in my basement laundry space, keeping the relative humidity below 50%. Additionally, wipe down the inside of the door glass with a dry towel after washing heavy items like towels or blankets, which hold onto excess moisture long after the cycle ends.

Comparing Cleaning Agents

Let's look at the cleaning agents you can use. I've tested dozens of products, from cheap DIY hacks to expensive commercial pods. Here is how they stack up in my laundry room.

Product	Price Range	Best For	Pros & Cons
White Vinegar	$3-5	Routine descaling	Cheap and effective, but smells strongly during the cycle.
Affresh Tablets	$10-12	Monthly maintenance	Easy to use and foams well, but struggles with heavy black mold.
Liquid Chlorine Bleach	$4-6	Killing severe mildew	Destroys bacteria fast, but can degrade rubber gaskets over time.
OxiClean Powder	$12-15	Lifting organic stains	Great for brightening, but requires very hot water to dissolve fully.