How to Clean a Smelly Washing Machine in 4 Steps (Front & Top Load)

TL;DR: A smelly washing machine is almost always caused by mold, mildew, or detergent residue trapped in the drum gasket, dispenser drawer, or drain filter. Run a hot cleaning cycle with white vinegar or washing machine cleaner, scrub the rubber gasket with a bleach solution, and leave the door open between loads. For persistent odor, check the drain pump filter and ensure the washer drains completely.

_Last reviewed: July 2026 · 6 min read_

That sour, musty smell coming from your washer means something is growing inside it — usually mold or mildew fed by leftover detergent, fabric softener, and moisture. The problem is worse in high-efficiency front-load machines because their tight-sealing doors trap humidity, but top-loaders aren't immune. The fix takes about 30 minutes and costs under $5 if you use household supplies.

Okoniq Property Hub lets you log each cleaning cycle, track when you last pulled the filter, and set reminders to wipe down the gasket weekly — keeping the washer fresh and preventing mold from taking hold.

Why does my washing machine smell like mildew or sewage?

Odor in a washing machine comes from three sources: mold growing in the rubber door gasket, detergent and fabric softener residue coating the drum and dispenser, or stagnant water sitting in the drain pump filter. Front-load washers are prone to all three because their horizontal drums hold water in low spots, and the gasket folds create dark, damp pockets where mold thrives. If the smell is a sewage odor rather than mildew, check the standpipe or drain hose for a venting problem — the P-trap may have dried out, letting sewer gas back up.

Use less detergent than you think you need. High-efficiency washers require 1-2 tablespoons of HE detergent per load, not the full cap. Excess soap doesn't rinse out completely and leaves a film that feeds mold. Skip fabric softener entirely if you're fighting odor — it coats the drum and gasket with a waxy residue that traps moisture. If you've been using pods, switch to liquid or powder for a few cycles to see if the smell improves.

Leaving the door closed after a load is the fastest way to create a mold problem. The drum stays wet, the gasket stays sealed, and airflow stops. Open the door wide after every wash and pull the detergent drawer open a few inches to let both areas dry. If you have a bathroom exhaust fan in an adjacent laundry room, run it for 30 minutes after the last load of the day to pull humidity out.

How do I clean the rubber gasket on a front-load washer?

The gasket is the #1 hiding place for mold in front-loaders. Mix 1 part household bleach with 4 parts water in a spray bottle, then spray the entire gasket fold — top, bottom, and sides. Let it sit for 5 minutes, then scrub with an old toothbrush or a small cleaning brush to dislodge black mold spots and slimy residue. Wipe everything down with a damp microfiber cloth, then run a rinse cycle with the door open to flush away bleach residue.

Check under the gasket folds for standing water, hair, coins, and small items like socks. These trap moisture and create biofilm. Pull the gasket back gently and wipe the hidden surfaces dry. Do this every week if you wash more than 10 loads — it takes 60 seconds and prevents mold from returning. If the gasket is torn or cracked, replace it before water leaks onto the floor during the spin cycle.

For stubborn mold that won't scrub off, use a paste of baking soda and water instead of bleach. Apply it to the stained areas, let it sit for 10 minutes, then scrub and rinse. If the odor persists after cleaning the gasket twice, the problem is likely deeper in the drum or drain system.

What's the best way to run a cleaning cycle and remove buildup inside the drum?

Most washers built after 2010 have a "Clean Washer" or "Tub Clean" cycle designed to run hot water without clothes. Select that cycle and add 2 cups of white vinegar directly to the drum, or use a commercial washing machine cleaner like Affresh or Tide Washing Machine Cleaner (one tablet per cycle). Do not add detergent. Let the cycle run completely — it usually takes 60-90 minutes and uses the hottest water setting available.

If your machine doesn't have a dedicated cleaning cycle, run the longest hot wash cycle with an extra rinse. The goal is to dissolve detergent buildup on the drum walls, spray arms, and internal hoses. Vinegar works because its acidity breaks down soap scum and mineral deposits without damaging rubber or plastic parts. Commercial cleaners use citric acid or oxygen bleach for the same effect.

Run a cleaning cycle once a month if you do more than 10 loads per week, or every 2-3 months for lighter use. After the cycle finishes, wipe the drum and door seal dry with a towel, then leave the door open for an hour. If you notice detergent clumps or white residue in the detergent drawer, pull the drawer out completely (most have a release tab) and soak it in hot water with a drop of dish soap. Scrub the drawer cavity inside the machine with a small brush, then rinse and replace.

| Cleaning Method | Cost | Best For | Frequency | |---------------------|----------|--------------|---------------| | White vinegar (2 cups) | $1 | Light odor, regular maintenance | Monthly | | Affresh or Tide tablets | $5-8 for 3 tablets | Heavy buildup, persistent smell | Every 30 loads or monthly | | Bleach (diluted 1:4) | $2 | Gasket mold, visible black spots | As needed for gasket cleaning |

Where is the drain pump filter and how do I clean it?

The drain pump filter catches lint, coins, and debris before they clog the drain hose. In front-load washers, it's behind a small access panel at the bottom front of the machine, usually on the lower right. In top-loaders, it may be inside the agitator or accessible from the back panel — consult your manual. Place a shallow pan or towels on the floor, then unscrew the filter cap slowly. Expect 1-2 cups of water to spill out as you remove it.

Pull out the filter and rinse it under hot water, removing any hair, lint, or sludge. If the filter smells like sewage or rotten eggs, the standing water inside has gone anaerobic. Scrub the filter with dish soap and a brush, then wipe the filter housing inside the machine with a damp cloth. Replace the filter, tighten it hand-tight, and run a rinse cycle to confirm no leaks.

Check the filter every 3 months, or sooner if the washer drains slowly or throws a drain error code. A clogged filter reduces spin speed, leaves clothes wetter than normal, and creates standing water where mold and bacteria grow. If you've never cleaned the filter and the machine is more than 2 years old, expect significant buildup — set aside 10 minutes for the first cleaning.

How do I prevent the smell from coming back?

Leave the door and detergent drawer open after every load to let air circulate. This single habit prevents 80% of odor problems. Wipe the gasket dry with a towel after the last load of the day, especially the bottom fold where water pools. If your laundry room is humid, run a dehumidifier or improve ventilation — a basement dehumidifier set to 50% relative humidity will keep both the room and the washer drier.

Use HE detergent and measure it correctly. Two tablespoons of liquid HE detergent is enough for a full load in a high-efficiency washer. More soap means more residue. Run a hot rinse cycle once a week with no detergent and no clothes to flush away any buildup before it hardens. If you use fabric softener, consider switching to wool dryer balls instead — they soften clothes without coating the drum.

Inspect the drain hose for kinks or loops that trap water. The hose should slope downward from the washer to the standpipe or drain with no sags. If the hose sits in standing water at the bottom of a standpipe, sewer gas can travel back up into the machine. Raise the hose end a few inches or install an air gap fitting. For recurring sewer odors, check that all nearby drains have working P-traps — a dried-out trap in a floor drain can send smells into the laundry room even if the washer itself is clean.

FAQ

How often should I clean my washing machine if I do 10+ loads per week?

Run a hot cleaning cycle with vinegar or a commercial cleaner once a month, wipe the gasket after every laundry day, and check the drain filter every 2-3 months. High use means more detergent residue and lint buildup.

Can I use bleach in a cleaning cycle instead of vinegar?

Yes, but never mix bleach and vinegar in the same cycle — the combination creates toxic chlorine gas. Run a bleach cycle (1 cup of bleach in the drum, hot water, no clothes) followed by an empty hot rinse cycle, or use vinegar in a separate cleaning the next month.

Will a smelly washer make my clothes smell bad even after washing?

Yes. Mold spores and bacteria transfer from the drum and gasket onto clean laundry during the rinse and spin cycles. If your clothes smell musty or sour right out of the washer, clean the machine before running another load.

My top-load washer smells even though it doesn't have a rubber gasket — where is the odor coming from?

Check under the agitator (it may lift off with a firm pull upward) for trapped fabric softener, detergent sludge, and standing water. Also inspect the drain pump filter and run a hot cleaning cycle with vinegar to flush the tub and internal hoses.

How do I know if the smell is from the washer or a plumbing problem?

If the odor is sulfur or sewage-like and gets worse when the washer drains, it's usually a venting or P-trap issue in the standpipe or laundry sink. If the smell is musty or sour and strongest when you open the washer door, the source is inside the machine.

This is educational information, not plumbing or appliance repair advice. For persistent drainage problems, leaks, or error codes, consult a licensed appliance technician or plumber.