How To Deep Clean A Washing Machine That Smells Musty

A washing machine is meant to clean clothes, not create odors. Yet many homeowners are surprised when they open their washer only to be greeted by a damp, earthy, or sour smell—commonly described as musty. This odor isn’t just unpleasant; it’s a sign of microbial growth, mold, mildew, and soap residue buildup within the machine. Left unaddressed, these contaminants can transfer to your laundry, leaving clothes smelling less than fresh despite being “clean.” The good news: a thorough deep cleaning can restore your washer’s performance and eliminate the stink for good.

This guide walks through the science behind the smell, practical cleaning techniques for both front-load and top-load machines, preventive strategies, and real-world insights from appliance care professionals. Whether you’ve noticed a faint odor or a full-blown funk, the solutions here will return your washer to optimal condition.

Why Washing Machines Develop Musty Smells

The root cause of musty odors in washing machines lies in moisture retention combined with organic debris. Modern high-efficiency (HE) washers, while water- and energy-efficient, often seal tightly and use lower water levels. This design reduces rinsing effectiveness and leaves behind damp environments where bacteria and mold thrive.

Key contributors include:

• Residual detergent and fabric softener: These substances cling to rubber gaskets, drain pumps, and drum crevices, forming a sticky biofilm that traps dirt and promotes microbial growth.
• Trapped moisture: Front-loaders, especially, retain water in the door seal and outer tub, creating an ideal breeding ground for mold.
• Infrequent maintenance: Most users never clean their washing machines, allowing grime to accumulate over months or years.
• Cold water washes: While eco-friendly, cold cycles don’t kill bacteria or dissolve grease and oils effectively.

According to Dr. Lena Patel, a microbiologist specializing in household environments, “The combination of warmth, humidity, and organic matter in washing machines makes them unintentional incubators for fungi and gram-negative bacteria. Regular sanitation isn’t optional—it’s essential for hygiene.”

“Even if your clothes come out looking clean, a smelly washer means microbes are still present. Deep cleaning every 1–3 months prevents long-term damage and protects your family’s health.” — Dr. Lena Patel, Microbial Hygiene Researcher

Step-by-Step Guide to Deep Cleaning Your Washing Machine

Performing a deep clean takes about 30–45 minutes and requires common household items. Follow this detailed process tailored for both front-loading and top-loading machines.

Step 1: Prepare the Machine

Run a quick empty cycle using hot water and no detergent to loosen surface debris. This pre-rinse helps subsequent cleaners work more effectively. Afterward, wipe down accessible surfaces with a dry cloth.

Step 2: Clean the Detergent and Softener Dispensers

Remove dispensers (if detachable) and soak them in warm, soapy water. Use an old toothbrush to scrub away residue. For stubborn buildup, soak in a 1:1 vinegar-water solution for 15 minutes before rinsing thoroughly.

Tip: Mark each dispenser compartment with a small dot of nail polish to remember their correct placement after cleaning.

Step 3: Treat the Door Seal (Front-Load Only)

Lift the rubber gasket around the door and inspect for black spots, slime, or trapped lint. Mix ½ cup baking soda with ¼ cup white vinegar to form a paste. Apply it to affected areas using a soft cloth or brush. Let sit for 10 minutes, then wipe clean with a damp microfiber cloth. Pay special attention to the bottom of the seal, where water pools.

Step 4: Run a Hot Sanitizing Cycle

Choose the hottest, longest cycle available (usually “Clean Washer,” “Tub Clean,” or “Sanitize”). Add one of the following cleaning agents:

• 2 cups of distilled white vinegar
• OR ¾ cup of bleach (do not mix with vinegar)
• OR a commercial washing machine cleaner (e.g., Affresh, Tide Washer Maintenance)

Pause the cycle after it fills and let the solution soak for 30–60 minutes. Resume to complete the wash and drain.

Step 5: Wipe Down Interior Surfaces

After the cycle ends, open the door and use a vinegar-dampened cloth to wipe the drum, edges, and any visible crevices. For persistent mildew stains, spray a mixture of equal parts water and hydrogen peroxide, wait 10 minutes, then wipe again.

Step 6: Clean the Drain Pump Filter

Locate the filter (typically behind a small access panel at the front bottom of front-loaders). Place towels underneath to catch residual water. Turn the filter counterclockwise to remove. Clear out lint, coins, and debris. Rinse under running water and reinstall securely.

Step 7: Leave the Door and Dispensers Open

After cleaning, leave the door and detergent drawer slightly ajar to promote air circulation and prevent moisture accumulation.

Do’s and Don’ts When Cleaning Your Washing Machine

Do’s	Don’ts
Use white vinegar and baking soda—they’re non-toxic and effective against biofilm.	Never mix bleach and vinegar; this creates toxic chlorine gas.
Clean the machine every 1–3 months, depending on usage.	Avoid overloading the washer, which reduces cleaning efficiency and increases moisture retention.
Wipe the door seal weekly to prevent mold buildup.	Don’t use regular dish soap or hand soap in the machine—they create excess suds and residue.
Run an empty hot cycle after washing diapers, gym clothes, or heavily soiled items.	Don’t ignore error codes related to drainage—they may indicate clogs that worsen odor issues.
Use high-efficiency (HE) detergent to minimize suds and residue.	Don’t store wet clothes in the washer for more than 1 hour—this breeds odor-causing bacteria.

Real Example: How One Family Eliminated Persistent Odors

The Rivera family had been battling a sour smell in their front-loading Samsung washer for over six months. Despite using scented detergents and dryer sheets, their towels came out smelling stale. They tried a single vinegar rinse but saw no improvement.

After consulting a technician, they learned their mistake: they were closing the door immediately after cycles, trapping moisture. They also used non-HE fabric softener, which coated the drum and pump.

Following a comprehensive deep clean—removing the dispensers, scrubbing the seal, running a bleach cycle, and clearing the filter—the odor vanished. They now leave the door open between uses and perform a maintenance cycle monthly. Six months later, their washer remains odor-free and operates more efficiently.

Preventive Maintenance Checklist

To avoid recurring musty smells, integrate these habits into your routine:

1. ✅ Run a cleaning cycle with vinegar or a dedicated cleaner every 4–6 weeks.
2. ✅ Wipe the door gasket and drum rim weekly with a dry or vinegar-dampened cloth.
3. ✅ Use only HE-formulated detergent and avoid excessive amounts.
4. ✅ Remove wet laundry promptly—within 30–60 minutes of cycle completion.
5. ✅ Leave the door and detergent drawer open when not in use.
6. ✅ Clean the lint filter (if applicable) and drain pump every 2–3 months.
7. ✅ Avoid using liquid fabric softener in the dispenser; opt for wool dryer balls instead.
8. ✅ Inspect hoses annually for cracks or leaks that could contribute to dampness.

Tip: Set a recurring calendar reminder labeled “Washer Deep Clean” to stay consistent.

Frequently Asked Questions

Can I use apple cider vinegar instead of white vinegar?

No. Apple cider vinegar contains sugars and colorants that can leave residues or stain internal components. Stick to clear, distilled white vinegar for best results.

Is bleach safe for my washing machine?

Yes, when used properly. Chlorine bleach is highly effective at killing mold and bacteria in washing machines. Use ¾ cup in a hot cycle once every few months. Never mix it with vinegar or ammonia-based products.

Why does my top-load washer smell if it doesn’t have a rubber seal?

Even top-loaders can develop odors due to stagnant water in the drum, detergent buildup, or a clogged drain hose. Residue accumulates under agitators or in hidden compartments. Regular cleaning cycles and wiping the inner lid area help prevent this.

Final Steps for Long-Term Freshness

Eliminating a musty smell is only half the battle. Sustained cleanliness requires consistent habits and awareness of how modern washing machines operate. Unlike older models that flushed away residue with large volumes of water, today’s efficient designs demand proactive care.

Think of your washing machine like a kitchen sink—it gets daily use, handles organic waste, and needs periodic sanitizing. By treating it with the same diligence, you ensure not only fresher laundry but also extend the appliance’s lifespan and maintain its efficiency.

Start today. Choose a cleaning method, gather your supplies, and dedicate 30 minutes to restoring your washer’s hygiene. Then, schedule ongoing maintenance to keep odors at bay. A clean machine means truly clean clothes—and peace of mind with every load.

💬 Take action now: Pick a day this week to deep clean your washing machine. Share your experience or ask questions in the comments—your insight could help others break free from musty laundry woes!