Why Does My Washing Machine Smell Like Mildew Simple Fixes That Work

If you open your washing machine only to be greeted by a musty, damp odor reminiscent of a basement after rain, you're not alone. Mildew smells in washing machines are common—especially in high-efficiency (HE) models—but they’re far from normal. That unpleasant stench isn’t just annoying; it can transfer to your clothes, towels, and linens, leaving them smelling less than clean. The good news: this issue is almost always fixable with straightforward maintenance and a few smart habits.

Mildew thrives in dark, moist environments—exactly the conditions inside many modern washing machines between cycles. Residual water, detergent buildup, fabric softener gunk, and trapped lint create the perfect breeding ground for mold and bacteria. Over time, these microbes produce volatile organic compounds responsible for the sour, earthy smell. But understanding why it happens is only half the battle. The real solution lies in consistent care and targeted cleaning.

Why Washing Machines Develop Mildew Smells

The root cause of a smelly washing machine isn't poor hygiene—it's design and usage patterns. Front-loading washers, in particular, are prone to odor problems due to their sealed doors and rubber door gaskets that trap moisture. Unlike older top-loaders that fully drain and air out, front-load HE machines use less water and spin at high speeds, which saves energy but leaves behind damp residues.

The rubber seal around the door collects water, hair, lint, and soap scum. If left unchecked, this becomes a microbial incubator. Additionally, detergent compartments and drain pumps often retain moisture and debris, further contributing to bacterial growth. Even hard water minerals or using too much detergent can compound the problem by creating a sticky film where microbes flourish.

As noted by Dr. Lisa Jakubowski, a microbiologist specializing in household environments:

“Washing machines are among the most microbially active appliances in homes. Without regular drying and cleaning, they become reservoirs for fungi and bacteria—even if they appear visually clean.” — Dr. Lisa Jakubowski, Microbial Ecology Research Lab

Step-by-Step Guide to Eliminate Mildew Odor

Killing the smell requires more than just running an empty cycle. You need to target every potential source of contamination. Follow this comprehensive 6-step process monthly—or immediately if odors persist.

1. Leave the Door and Dispenser Open After Use
   After each wash, prop the door and detergent drawer slightly ajar. This allows airflow and prevents moisture from stagnating. It’s the simplest and most overlooked preventive step.
2. Clean the Door Gasket (Front-Loaders)
   Pull back the rubber seal and inspect the underside. Wipe away any black specks, slime, or grime with a cloth dampened in a mix of equal parts white vinegar and water. For stubborn buildup, use a soft brush. Pay special attention to the bottom of the seal, where water pools.
3. Run a Hot Cleaning Cycle
   Set your machine to the hottest, longest cycle (usually “Clean Washer” or “Tub Clean”). Add one of the following:
   • 2 cups of distilled white vinegar
   • OR ¾ cup of bleach (if your machine manual allows it)
   • OR a commercial washer cleaner tablet
   Run the cycle without clothes. Vinegar dissolves mineral deposits and kills mildew; bleach sanitizes effectively but should be used sparingly to avoid damaging seals over time.
4. Deep-Clean the Detergent Drawer
   Remove the dispenser tray according to your model’s instructions. Soak it in warm vinegar water for 30 minutes. Scrub crevices with an old toothbrush. Rinse thoroughly before reinserting.
5. Check and Clean the Drain Pump Filter
   Located near the bottom front of most front-loaders, this filter catches lint, coins, and debris. Place a towel underneath, unscrew the access panel, and remove the filter. Empty gunk into a trash can, rinse under running water, and replace securely. Do this every 1–2 months.
6. Wipe Down Interior Surfaces
   After the cleaning cycle, use a microfiber cloth dipped in vinegar solution to wipe the drum, especially around seams and behind the agitator (in top-loaders). Dry completely with a separate towel.

Tip: Never use chlorine bleach on stainless steel drums unless specified by the manufacturer—vinegar is safer and equally effective for routine maintenance.

Do’s and Don’ts: Maintaining a Fresh-Smelling Machine

Prevention is key. Even after eliminating existing odors, poor habits can bring them back within weeks. Use this table as a quick-reference guide for best practices.

Do’s	Don’ts
Use high-efficiency (HE) detergent only	Overload the machine or use excessive detergent
Measure detergent precisely—less is more	Use liquid fabric softener regularly (it coats components)
Wash towels and gym clothes at higher temperatures when possible	Let wet clothes sit in the drum for hours after the cycle ends
Run a hot tub-clean cycle monthly	Ignore visible mold or persistent smells
Air out the drum after every load	Store the machine in a cold, unventilated space like a basement without dehumidification

Real Example: How Sarah Fixed Her Smelly Washer

Sarah, a mother of two in Portland, Oregon, noticed her towels had started smelling musty despite using the same detergent and routine. Her three-year-old front-loading LG washer developed a strong mildew odor she couldn’t ignore. At first, she assumed the towels were the issue and rewashed them multiple times—only for the smell to return.

After reading about washer maintenance, she followed the deep-cleaning steps outlined above. She removed the detergent drawer, cleaned the gasket (finding a thick layer of black gunk underneath), ran a vinegar cycle, and cleared the drain filter—which was clogged with pet hair and sand from beach towels.

The result? The odor vanished after one thorough cleaning. More importantly, by leaving the door open after each use and switching to measured HE detergent, she prevented recurrence. Six months later, her machine still runs fresh.

“I thought I needed a new washer. Turns out all it needed was some attention—and a little vinegar.” — Sarah T., homeowner and DIY enthusiast

Alternative Solutions and Natural Remedies

While vinegar and bleach are effective, some homeowners prefer gentler or alternative methods. These options work well for routine upkeep but may require more frequent application.

• Baking Soda + Vinegar Combo: Add ½ cup baking soda to the drum, then pour 1 cup vinegar into the detergent dispenser. Run a hot cycle. The fizzing action helps loosen residue.
• Citric Acid Packets: Found in home brewing or cleaning sections, citric acid dissolves limescale and inhibits microbial growth. Use one packet per cleaning cycle.
• Eucalyptus or Tea Tree Oil (Optional): Add 10 drops of antimicrobial essential oil to a vinegar wash cycle for a fresher scent. Note: Oils can leave residue; use sparingly and follow with a rinse-only cycle.

Tip: Avoid “washing machine odor neutralizers” that merely mask smells. Focus on removing the source, not covering it up.

Monthly Maintenance Checklist

To keep your washing machine odor-free year-round, follow this actionable checklist every 30 days—or more often in humid climates.

• ✅ Run a hot cleaning cycle with 2 cups white vinegar
• ✅ Wipe down the door gasket with vinegar-soaked cloth
• ✅ Remove and clean the detergent drawer
• ✅ Check and empty the drain pump filter
• ✅ Inspect the exterior vent (if applicable) for blockages
• ✅ Confirm the floor beneath the machine is dry and level
• ✅ Verify hoses for leaks or bulges (replace every 5 years)

Frequently Asked Questions

Can I use apple cider vinegar instead of white vinegar?

No. While both are acidic, apple cider vinegar contains colorants and sugars that can stain or feed microbial growth. Stick to clear, distilled white vinegar for cleaning.

Is it safe to mix vinegar and baking soda in the washing machine?

Yes, but with caveats. The reaction creates foam that can help dislodge grime, but excessive foaming may trigger error codes in sensitive HE machines. Use moderate amounts and avoid overfilling compartments.

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

Even top-loading machines can develop odors. Stagnant water in the drum, detergent buildup in the agitator, or infrequent cleaning of the lid area can harbor bacteria. Run monthly hot cycles and wipe down interior surfaces regularly.

Conclusion: Take Control of Your Machine’s Freshness

A smelly washing machine doesn’t mean it’s broken—it means it needs care. Mildew odors are preventable and treatable with consistent attention. By integrating simple habits like leaving the door open, measuring detergent correctly, and performing monthly deep cleans, you can maintain a truly clean appliance. Your clothes, towels, and nose will thank you.

Don’t wait until the smell becomes unbearable. Start today: run a vinegar cycle, inspect the gasket, and commit to a maintenance routine. A fresh-smelling washer isn’t a luxury—it’s a standard you can achieve with minimal effort.

💬 Have a tip that worked for your smelly washer? Share your experience in the comments and help others breathe easier with every load.