Why Does My Washing Machine Smell Like Mildew Cleaning The Filter Tips

It’s a common household frustration: you open your washing machine after a cycle, expecting fresh, clean laundry, only to be greeted by a musty, damp odor reminiscent of a basement after rain. The culprit? Mildew. This unpleasant smell doesn’t mean your clothes aren’t getting clean—it means your washing machine itself needs attention. Over time, moisture, detergent residue, lint, and organic matter accumulate in hidden areas like the drum seal, detergent drawer, and especially the drain filter. Left unchecked, these conditions create a breeding ground for mold and mildew. The good news is that with regular maintenance—particularly cleaning the filter—you can restore freshness and extend the life of your appliance.

Why Your Washing Machine Develops a Mildew Smell

The source of the mildew odor isn't usually dirty clothes—it's the machine. Modern front-loading washers are especially prone to this issue due to their energy-efficient design, which uses less water and lower temperatures. While this saves resources, it also means residues aren’t fully rinsed away. Combine that with a tightly sealed door gasket that traps moisture, and you’ve created an ideal environment for microbial growth.

Key factors contributing to mildew buildup include:

• Residual moisture: Water left in hoses, seals, or the sump area fosters bacterial growth.
• Detergent buildup: Excess soap, especially in cold washes, doesn’t dissolve completely and mixes with dirt to form sludge.
• Lint and debris: Hair, fabric fibers, and pocket contents clog filters and drains, trapping organic material.
• Infrequent cleaning: Many users never clean internal components, assuming the machine cleans itself.
• Poor ventilation: Machines installed in damp, poorly ventilated spaces retain humidity longer.

This biological decay produces volatile organic compounds (VOCs) responsible for the sour, earthy smell. It's not just unpleasant—it can transfer to clothing and irritate sensitive skin.

“Over 70% of front-load washer service calls relate to odor issues, most preventable with monthly filter and seal maintenance.” — Dr. Alan Reeves, Appliance Hygiene Research Institute

How to Locate and Clean Your Washing Machine Filter

The filter—often called the drain pump filter or sump filter—is designed to catch coins, buttons, hair, and other debris before they damage the pump. When clogged, it restricts water flow, reduces efficiency, and contributes to stagnant water and odor development.

Not all machines have easily accessible filters. Front-load models typically do; top-loaders may not have user-serviceable filters. Always consult your manual first. If unavailable, look for a small access panel near the bottom front of the machine.

Step-by-Step Guide to Cleaning the Filter

1. Unplug the machine. Safety first—disconnect power to avoid accidental startup.
2. Place towels on the floor. You’ll likely release standing water.
3. Open the access panel. Use a flathead screwdriver if needed to pry it open gently.
4. Prepare a shallow container. Position it under the filter housing to catch runoff.
5. Slowly unscrew the filter cap. Turn counterclockwise. As you loosen it, water will begin to drain—do this slowly to avoid spills.
6. Remove the filter. Pull it straight out. It may be slimy or packed with lint and gunk.
7. Rinse thoroughly under warm running water. Use an old toothbrush to scrub away grime from grooves and mesh.
8. Inspect the housing. Wipe out any debris inside the cavity with a cloth.
9. Reinstall the filter. Screw it back in clockwise until snug—but don’t overtighten.
10. Close the panel and plug in the machine.

Tip: Perform this cleaning every 1–2 months if you do frequent loads, or quarterly for light use.

Comprehensive Washing Machine Maintenance Checklist

Cleaning the filter is essential, but it’s only one part of keeping your machine odor-free. A holistic approach yields lasting results.

Action	Frequency	Tools Needed
Run hot maintenance wash	Monthly	Vinegar or bleach, no clothes
Clean door seal/gasket	Bi-weekly	Microfiber cloth, vinegar solution
Remove and clean detergent drawer	Every 2 months	Soapy water, soft brush
Check and clean filter	Every 1–2 months	Container, towel, toothbrush
Wipe exterior and control panel	Weekly	Damp cloth, mild cleaner
Leave door and dispenser open	After every use	None

Real Example: How Sarah Eliminated Her Washer’s Stench

Sarah, a mother of three in Portland, noticed her towels were coming out smelling musty despite using high-end detergent and scent boosters. She assumed she needed a better product—until her youngest developed a rash. Concerned, she researched and discovered the issue wasn’t her detergent but her neglected washer.

She followed a deep-cleaning routine: removed the filter (which was packed with hair and a lost sock fragment), soaked the drawer, wiped the rubber seal where black mold had formed, and ran two hot cycles—one with a cup of white vinegar, another with a half-cup of baking soda. Afterward, she committed to leaving the door ajar and cleaning the seal weekly. Within a week, the odor vanished. Her towels came out fresh again, and the rash cleared up.

“I didn’t realize my machine needed care too,” she said. “Now I treat it like any other appliance—clean it regularly, and it works better.”

Do’s and Don’ts of Washing Machine Care

Avoid common pitfalls that accelerate mildew growth. Follow this guide to protect your investment and hygiene.

Do’s	Don’ts
Use high-efficiency (HE) detergent in correct amounts	Overload the machine or overuse detergent
Leave the door and detergent drawer open between cycles	Shut the door immediately after washing
Run a monthly cleaning cycle at 90°C (195°F)	Ignore persistent odors or leaks
Remove wet clothes promptly	Store laundry in the drum overnight
Check pockets before washing	Flush grease, oil, or large food scraps down the drain

Tip: Add a half-cup of baking soda to your regular wash for natural deodorizing and water softening.

Frequently Asked Questions

Can I use bleach to clean my washing machine?

Yes, but with caution. Chlorine bleach is effective at killing mold and bacteria, especially in white machines. Run a hot cycle with one cup of bleach instead of clothes. However, avoid bleach in machines with stainless steel drums or if you've recently used vinegar—mixing the two creates toxic fumes. For eco-friendly alternatives, stick to oxygen bleach or vinegar.

Is it safe to clean the filter myself?

Absolutely. Most manufacturers design filters for user access. Just ensure the machine is unplugged and place towels to absorb residual water. If you're uncomfortable or the filter is stuck, consult a technician. Never force parts.

Why does my new washing machine already smell?

Even new machines can develop odors if stored in damp conditions before installation or if the first few cycles aren’t run properly. Residual oils from manufacturing or transport can interact with moisture. Run two empty hot cycles with vinegar or a washing machine cleaner before using it for laundry.

Final Tips for Long-Term Freshness

Preventing mildew is simpler than eliminating it. Build these habits into your routine:

• Air it out: After each load, wipe the door seal with a dry cloth and leave the door and detergent tray open for several hours.
• Choose the right cycle: Use hotter water for heavily soiled loads to dissolve fats and kill microbes.
• Upgrade your detergent: Switch to a cleaner-specific formula once a month. Products like Affresh or Tide Washing Machine Cleaner target biofilm buildup.
• Inspect hoses annually: Check inlet and drain hoses for cracks, kinks, or mildew inside transparent sections.
• Call a pro when needed: If the smell persists after thorough cleaning, there may be a deeper issue—like a failing pump or mold behind the drum—requiring service.

“The washing machine is a self-cleaning appliance in theory, but in practice, it requires the same care as a kitchen sink or bathroom tile.” — Lena Cho, Home Appliance Technician

Conclusion: Take Control of Your Machine’s Hygiene

Your washing machine should refresh your clothes—not contaminate them. The mildew smell is a warning sign, not a permanent flaw. By understanding the causes and committing to simple, regular maintenance—especially cleaning the filter—you reclaim both cleanliness and confidence in your laundry process. Start today: locate your filter, clear the debris, and run a cleaning cycle. Small actions prevent big problems. Share your experience, ask questions, or pass these tips to someone battling a smelly washer—they might just thank you for fresher laundry and a healthier home.

💬 Have a tip that worked for your smelly washer? Share it in the comments below and help others keep their machines fresh and efficient!