What Your Washing Machine Smell Is Telling You

Your washing machine cleans everything you own, so it feels backward when it starts smelling like a damp gym bag.

The smell itself is the diagnosis. Musty means mold in the seal or the drum. Sewage means a plumbing fault behind the machine. Rotten egg can mean bacteria, or a gas leak you treat as an emergency. Burning means stop the load right now.

Here are the five washing machine smells, what each one is telling you, how to clear it, and the cleaning schedule that keeps it from creeping back.

Why Your Washing Machine Smells

Naming the smell is the fastest route to the fix, because each odor comes from a different place. One lives in the rubber seal, one lives in the drain behind the wall, and one is a safety problem you do not touch at all. Here are the most common reasons why washing machines smell bad, smell by smell.

Musty or Mildew Smell

This is the most common complaint, especially with front-load washers. Front-loaders seal tightly to stop leaks, and that same design traps water and detergent film in the horizontal drum and the folds of the rubber door gasket. Those warm, damp pockets are exactly where mold, bacteria, and biofilm grow, according to Consumer Reports.

Cold-wash habits make it worse. A 2024 review of washing machine microbiology found that machines run mostly on low-temperature cycles build up a more diverse microbial population and biofilm on the drum, the gasket, and the detergent drawer. Washing cold saves energy, but it does not clean the machine itself.

The EPA states the underlying rule plainly: the key to mold control is moisture control ⁽¹⁾. If water sits in the drum, the drain hose, or the gasket folds after a wash, you get that wet-towel smell. You may even find a sock that has been quietly molding in the seal for a month.

Sewage or Drain Smell

If your laundry room smells like a sewer, act fast. That odor is often sewer gas drifting back up the drain, and sewer gas (hydrogen sulfide) is both toxic and flammable, per OSHA ⁽²⁾.

The usual cause is a dry p-trap. The p-trap is the curved section of drain pipe that holds a plug of water, and that water is the only thing blocking gas from the pipes below. When a drain sits unused, the water simply evaporates and the seal is gone. A laundry standpipe on a machine you have not run in weeks, or the floor drain next to it that never gets used at all, are the classic offenders. A clogged drain or a blocked plumbing vent on the roof causes the same backup.

If deep cleaning the machine does not fix the smell, the problem is in the plumbing, not the appliance.

Rotten Egg (Sulfur) Smell

A sulfur or “rotten egg” smell usually means bacteria are feeding on trapped organic matter like hair, lint, and soap scum. As they break it down, they give off a sulfur gas that collects in the drum, drain, or filter.

One caution before you reach for the vinegar. If you have a gas dryer, water heater, or gas line near the laundry room, do not assume the smell is bacteria. Natural gas is odorless on its own, so utilities add a chemical (mercaptan) that smells like rotten eggs specifically so a leak is easy to notice (PHMSA). If the smell is strong, or you feel lightheaded, treat it as a gas smell first.

Gas Smell

A distinct gas smell is an emergency, and it is almost never the washer. Washing machines run on electricity, not gas, so a gas odor in the laundry room comes from a nearby gas dryer, water heater, or supply line.

Do not troubleshoot it like a cleaning problem. Leave the smell alone, avoid flipping any switches or unplugging anything (a spark can ignite the gas), get everyone out of the house, and call your gas company or 911 from outside.

Burning or Electrical Smell

A burning odor means a mechanical fault, usually a worn drive belt, a failing motor, faulty wiring, or an overheating wall outlet. It is never a hygiene issue you can scrub away.

How to Get Rid of Washing Machine Smells

Most washing machine smells clear in an afternoon with vinegar, a brush, and an empty hot cycle. Work through the machine in order: the gasket and drum first, then the dispenser, the drain, and the filter.

Vinegar and Water Solution

Distilled white vinegar cuts through soap scum and neutralizes odor, which makes it the right first move on a musty machine.

1. Mix your spray: Combine equal parts distilled white vinegar and water in a spray bottle. Add a little lemon juice for a fresher scent if you like.
2. Spray the interior: Coat the entire drum. Pay special attention to the rubber gasket (the seal around the door). Pull back the folds and spray deep inside where mold hides.
3. Scrub, then dry: Wipe everything down with a damp microfiber cloth, and work an old toothbrush into stubborn mold spots on the gasket. The EPA’s advice for mold on any hard surface is the same two-step: scrub with detergent and water, then dry completely. So finish with a dry cloth instead of leaving the seal damp.
4. Wipe the exterior: Give the outside of the machine and the glass door a wipe, avoiding the electronic control panel.

Clean Out the Pipes

A sewage smell almost always traces back to the drain, and the fix is often a gallon of water.

1. Refill the p-trap: Pour a gallon of water down the drain standpipe, and down any floor drain nearby. If the trap had dried out, this rebuilds the water seal that blocks sewer gas, usually within minutes.
2. Check the drain hose: Make sure the hose is not kinked or pushed too far down the standpipe, which can siphon dirty water back into the machine.
3. Clear the vent pipe: If your plumbing vent on the roof is clogged with leaves or a bird nest, sewer gas can back up. If you are not comfortable getting on the roof, call a plumber.
4. Keep the trap wet: Run water down any drain you rarely use, floor drains included, every week or two. A trap that never dries out never lets gas through.

Clean the Detergent Dispenser

The soap drawer does not rinse itself clean. It is one of the three places biofilm settles into, along with the drum and the gasket, because it sits damp between loads.

1. Remove the drawer: Most dispensers have a release tab so you can pull them fully out.
2. Soak it: Submerge the drawer in hot, soapy water for an hour to soften hardened detergent.
3. Scrub the cavity: While the drawer soaks, look inside the slot where it sits. Use a pipe cleaner or bottle brush to scrub the water jets and the top of the compartment.
4. Dry and replace: Scrub the drawer clean, dry it, and slide it back in. Leave it open a crack afterward so it can air out.

Deep Clean the Drum

Once you have scrubbed the parts you can reach, clean the parts you cannot.

1. Choose your cleaner: Use a commercial tablet (like Affresh), two cups of distilled white vinegar, or half a cup of bleach. Never mix bleach and vinegar: bleach plus an acid like vinegar gives off chlorine gas, which irritates your eyes, nose, and throat, according to the Washington State Department of Health ⁽³⁾.
2. Select the cycle: Choose the “Tub Clean” setting if you have one. Otherwise, pick the longest cycle at the hottest water temperature. Heat does half the work here, so this is not the cycle to run cold.
3. Run it empty: Let the machine run with no laundry inside.
4. Air it out: Leave the door open as soon as the cycle ends so the moisture escapes.

Change Your Laundry Habits

Sometimes the smell comes from how you wash, not the machine itself.

If you have a high-efficiency (HE) washer, use HE detergent. Regular soap makes too many suds for an HE machine to rinse away, and that leftover film coats the drum and feeds odor-causing bacteria, as Consumer Reports notes.

Stop overdosing the detergent, too. More soap does not mean cleaner clothes, it just means more residue for bacteria to feed on. Measure to the fill line for your load size instead of eyeballing the cap.

Then look at your temperature dial. If nearly every load you run is cold, the machine never gets a heat treatment, and that is the condition biofilm likes best. You do not have to start washing your clothes hot. You do have to give the machine itself one hot cycle a month, which is the maintenance wash the schedule below is built around.

Leave the Door Open

This is the golden rule of washing machine maintenance. Closing the door right after a cycle traps heat and humidity inside, which creates a greenhouse for mildew.

The timing matters more than people expect. The EPA’s guidance on damp material is that mold usually will not grow if things dry out within 24 to 48 hours, and a sealed drum beaded with warm water is not drying out. So leave the door ajar after every load (or all the time, if the layout allows), and wipe the glass and the rubber seal with a dry dish towel to clear standing water.

Do not leave a finished load sitting overnight either. Wet laundry in a closed drum is the fastest way to move the smell out of the machine and into your clothes. If your laundry room stays damp, run a dehumidifier nearby.

Clean Your Filter

Many front-loaders have a debris filter behind a small door near the floor. Cleaning this filter is messy but necessary, and it clears the lint, coins, buttons, and small socks that would otherwise rot in the pump. Whirlpool and LG both recommend cleaning it about once a month.

1. Prep the area: Lay down an old towel and open the small access door.
2. Drain the water: Unclip the small emergency drain tube, remove the plug, and let the trapped water drain into a shallow bowl.
3. Remove debris: Unscrew the filter cap, pull it out, and clear the lint, coins, hair, and sludge caught inside.
4. Rinse and replace: Wash the filter in the sink with hot soapy water, slide it back in, and screw it tight.

How Often to Clean a Washing Machine

Washing machine smells come back when maintenance is occasional. Put these four jobs on a schedule and the machine stays neutral instead of swinging between fine and foul.

• After every load: Wipe the gasket and door glass dry, and leave the door and the detergent drawer open.
• Every week or two: Pour water down any drain you do not use, including the laundry floor drain, so its trap seal cannot evaporate.
• Monthly: Run a hot tub-clean cycle with a machine cleaner, vinegar, or bleach. LG puts Tub Clean on a monthly schedule, and the washing machine microbiology research reports the same thing: manufacturers advise a monthly high-temperature maintenance wash to counteract biofilm build-up.
• Monthly: Empty and rinse the drain pump filter. Whirlpool and LG both call for it monthly, and it is the step almost everyone skips.

Already musty? Escalate before you settle into the routine. LG suggests running Tub Clean once a week for three weeks when a machine already smells, since years of buildup can take a few passes to break down.

FAQs About Washing Machine Smells

Clean Machine, Clean Clothes

A smelly washing machine is telling you something specific. Musty means mold has moved into the gasket and drum, sewage means the drain is no longer sealed, and burning or gas means stop and get help.

Match the smell to its cause before you buy anything. Most musty and sewage odors clear with a hot vinegar or bleach cycle, a scrubbed gasket, a gallon of water down the drain, and a door left open afterward. Then hold the monthly schedule, because the machine that never smells is the one that gets a hot cycle and a clean filter every month.