Key takeaways

  • The smell is mold and bacteria growing in a film of detergent residue, body soil, and lint that never dries out, usually in the outer tub you cannot see.
  • High-efficiency top loaders with an impeller instead of a center agitator smell more often than old deep-fill machines, because they use less water and cooler temperatures.
  • Too much detergent and liquid fabric softener are the most common cause. They do not fully rinse away, and the leftover film is what feeds the mold.
  • The fix: run a hot cleaning cycle with bleach or a washer cleaner tablet, scrub the dispenser cups and the rim under the lid, then leave the lid open between loads.
  • If the smell returns within days, suspect water sitting in the outer tub from a slow or blocked drain, not a cleaning problem.

What’s in this guide

Your top load washer smells like mildew because water, detergent residue, lint, and skin oils build up into a soft film inside parts of the machine that never dry out, and mold and odor-causing bacteria live in that film. You smell it most when you open the lid on a warm day or start a cold cycle, because the moisture releases the odor back into the air.

Almost every case comes down to three habits: too much detergent, too much liquid fabric softener, and wet laundry left sitting in a closed drum. Fix those and run one hot cleaning cycle, and most machines come back within a day.

Why does my top load washer smell like mildew?

Mold needs moisture, warmth, and food. A washer supplies all three. The food is the residue left behind when detergent and softener do not fully rinse, mixed with lint and the soil that came off your clothes.

That residue coats plastic and rubber surfaces in a thin biofilm. Biofilm is slippery, it resists plain rinsing, and it holds moisture against the surface long after the cycle ends. Once it establishes, cold water and normal detergent will not remove it.

This is why a machine that smells fine for two years suddenly turns on you. Nothing broke. The film simply reached the thickness where you can smell it.

Where exactly is the smell coming from?

In a top loader, the odor usually comes from the outer tub, which is the sealed plastic shell around the basket you load clothes into. Water sits in the gap between the two, and you cannot see or wipe that space. It is the single most common hiding spot in a top load machine.

The other spots worth checking, in order of how often they cause trouble:

  • The fabric softener dispenser cup, often on top of the agitator or molded into the rim. Softener is thick and it clings, so this cup is frequently the worst-smelling part of the whole machine.
  • The bleach and detergent dispenser channels, where diluted product pools after the cycle.
  • The underside of the lid and the plastic rim around the top of the tub, where splashes dry slowly.
  • The drain hose and the standpipe it sits in. A sour, sewer-like smell rather than a musty one usually points here.
  • Under the agitator cap on older machines, where lint and hair collect around the shaft.

Sniff each one directly before you start cleaning. If the dispenser cup is the source, you can solve this in ten minutes with hot water and a bottle brush.

Is my HE top loader more likely to stink than an old one?

Yes, noticeably. High-efficiency top loaders use an impeller, a low disc or plate at the bottom, instead of a tall center agitator, and they fill with a fraction of the water an older machine used. Less water means less rinsing, and cold-water washing means detergent surfactants work less completely.

Old deep-fill machines flooded the tub and drained hard, which flushed residue out by brute force. HE machines are gentler on water and energy, and the trade-off shows up as film. Samsung, LG, and Whirlpool HE top loaders all attract the same complaint, which is why nearly all of them ship with a dedicated Tub Clean or Clean Washer cycle.

None of that means your machine is defective. It means it needs a maintenance cycle roughly monthly, the same way a dishwasher needs its filter emptied.

Am I using too much detergent or fabric softener?

Probably. The fill line on most detergent caps sits far below the top of the cap, and most people pour past it. In an HE top loader that uses a low water level, extra detergent has nowhere to go, so it stays in the machine and in your clothes.

Liquid fabric softener is worse. It works by depositing a waxy cationic coating on fibers, and that coating lands on the tub, the dispenser, and the hoses too. If your washer smells and you use liquid softener in every load, stop the softener for a month and see what happens.

Wool dryer balls do the softening job without leaving anything in the washer. If you make or wash handmade items, softener also flattens the loft of yarn, so it is not doing your chunky knit and crochet blankets any favors either.

Use HE detergent in an HE machine, measure to the line, and use less than you think for lightly soiled loads. Powder detergent rinses cleaner than liquid in hard water areas, if you are in one.

How do I get the mildew smell out of a top load washer?

Run one hot cleaning cycle with a disinfectant, then hand-clean the parts the cycle cannot reach. Do it in this order, because the cycle loosens residue and the hand-cleaning removes what it lifts.

  1. Pull out the fabric softener cup and any removable dispenser inserts. Soak them in hot water with a squeeze of dish soap, then scrub with an old toothbrush or bottle brush.
  2. Wipe the underside of the lid and the plastic rim around the tub with hot soapy water. Get into the groove where the rim meets the basket.
  3. Start the Tub Clean, Clean Washer, or Self Clean cycle with an empty drum. If your machine has no such cycle, choose the hottest, largest, longest wash with an extra rinse.
  4. Add either one cup of liquid chlorine bleach or a washing machine cleaner tablet. Put bleach in the bleach dispenser, not the drum. Put a tablet straight in the empty drum.
  5. Run the cycle to completion. Then run a second short hot cycle with nothing added, to clear the bleach.
  6. Leave the lid open for several hours so the tub dries fully.

Do not mix bleach with vinegar, and do not mix bleach with anything containing ammonia. That combination releases chlorine gas, and a laundry closet is a small space.

If clothes and towels already smell, wash them separately on hot with a full dose of detergent and half a cup of oxygen bleach, and dry them completely. A towel that goes into the dryer still slightly damp will smell sour again by morning.

What if the smell comes back within a week?

A smell that returns within days is a drainage problem, not a cleaning problem. Water is sitting somewhere it should not, and no amount of cleaner will fix that.

Check the drain hose first. It should sit in the standpipe about 6 to 8 inches deep, held loosely, with an air gap around it. If it is jammed all the way down or taped tight, the machine can siphon and hold dirty water in the outer tub.

Then check whether the standpipe drains slowly. If you see water rise near the top of the pipe during the spin, the drain line is partly clogged with lint and soap scum, and the machine finishes each cycle sitting in a puddle. That is a plumbing job, not a laundry job.

Some top loaders have a coin trap or a pump filter near the base. Check your manual before you go looking, because most HE top loaders do not have a user-accessible one, and the ones that do will dump a cup of water when you open them.

How do I keep it from coming back?

Dry it out and feed it less. Those two things prevent nearly every recurrence.

  • Leave the lid open between loads. This is the single most effective habit, and it costs nothing.
  • Move wet laundry to the dryer as soon as the cycle ends. Overnight in a closed drum is how a fresh load turns sour.
  • Run a hot cleaning cycle once a month. Put it on the same day you do another monthly chore so you remember.
  • Cut liquid fabric softener, or drop it entirely.
  • Wash towels and gym clothes on hot at least occasionally, so the machine gets a hot flush from real laundry too.
  • Wipe the dispenser cup every few weeks rather than waiting for it to crust over.

One caution about hot sanitize cycles: they are hard on decorated garments. If your family wears shirts made with heat transfer vinyl, keep those on warm or cold and let the towels take the hot cycles instead.

Do I need washer cleaner tablets, or will vinegar work?

Bleach or a washer cleaner tablet works better than vinegar on mildew, and it is not close. Vinegar is a weak acid that dissolves mineral scale and soap scum, which is useful, but it does not kill established biofilm well and it does not bleach out the stains it leaves behind.

Washer cleaner tablets are mostly sodium percarbonate, which is oxygen bleach, sometimes with surfactants that help lift the film. They are convenient and they will not damage seals. Plain liquid chlorine bleach through the bleach dispenser costs less and is at least as effective at killing what smells.

Vinegar does have a job here. Use it for the removable dispenser cups and the lid rim, where the scale is visible and you can scrub. Just keep it away from any cycle that also has bleach in it.

What you do not need is a scented booster, a permanent tub freshener, or a fragrance pod. Those mask an odor rather than removing its source, and the added product becomes more residue. If you are shopping for cleaning supplies anyway, our current household deals are the better place to spend that money.

Frequently asked questions

Can I use bleach and vinegar together to clean my washer?

No. Chlorine bleach mixed with acid releases chlorine gas, which is dangerous in a small laundry room. Use one or the other, and if you use both on different days, run a rinse cycle in between.

Does leaving the lid open really make a difference?

Yes, more than most people expect. Mold needs sustained moisture, and an open lid lets the tub and rim dry within a few hours instead of staying damp until the next load. If you have small children or pets and cannot leave the lid up, at least prop it open when the room is empty.

How often should I run a cleaning cycle on a top load washer?

Once a month for a high-efficiency top loader, or every two months if you wash mostly on hot and skip fabric softener. Large families washing daily should stay on the monthly schedule. If you already smell mildew, do the deep clean first and then start the monthly routine.

Why do my towels still smell even after a clean wash?

Towels hold detergent and softener residue in their loops, and that residue holds bacteria. Wash them on hot with oxygen bleach and no softener, then dry them fully rather than pulling them out slightly damp. It usually takes two washes to reset a badly soured set.

Is a smelly washing machine a health risk?

For most healthy households it is an odor nuisance rather than a hazard, but the same biofilm can transfer bacteria back onto clothes. It matters more if someone in the house has asthma, a mold allergy, or a weakened immune system. In those cases, clean the machine promptly and wash on hotter settings.

Start with the fabric softener cup and the hot cleaning cycle before you assume anything is broken. Most top loaders that smell like mildew are simply overdue for a flush and are being fed too much product, and September is a reasonable time to fold it into the fall reset you are probably already doing around the house. This guide was checked and updated on September 10, 2026.

If the smell survives a proper deep clean and comes back inside a week, stop cleaning and go look at the drain hose height and the standpipe. And while you are in laundry-fixing mode, the same residue problem is part of why some stains, including washable marker marks on kids’ clothes, survive a cold cycle that should have handled them. Less detergent, hotter water, and a dry tub solve a surprising number of laundry complaints, and a clear dryer vent handles the rest at once.