Why Does Your Washer Smell? Common Causes and How to Fix Them

Why Washing Machines Start to Smell

Modern washers are designed to use significantly less water than older machines. That’s great for efficiency, but it also means detergent, fabric softener, lint, body oils, and dirt can accumulate inside areas you can’t easily see.

The inside of a washer is also warm and damp after a cycle. Add organic residue and limited airflow, and you have an ideal environment for bacteria, mildew, and mold. The problem is particularly common with front-load washing machines, although top-load washers can develop odors as well. Here are the areas we usually investigate first.

1. Mold and Buildup Inside the Door Gasket

If you have a front-load washer, start with the rubber seal around the door. Pull the gasket back carefully and look inside the folds. You may find black or grey mold spots, slimy detergent residue, hair and lint, small pieces of clothing, coins or other debris, or standing water.

The gasket is designed to prevent water from escaping through the door, but its folds also trap moisture. We frequently find washers where the visible part of the gasket looks perfectly clean while the underside is covered with residue.

Clean the gasket with a cloth and an appropriate washing-machine cleaner. Pay particular attention to the lower section, where water tends to collect. If the gasket has become heavily contaminated or permanently stained with mold, cleaning may improve the smell without completely eliminating it — in severe cases, replacing the door boot may be the better solution.

2. Too Much Detergent

More detergent does not mean cleaner clothes. This is one of the most common causes of washing machine odor. High-efficiency washers use relatively little water, and when too much detergent is added, the machine may not be able to rinse all of it away. The leftover soap mixes with lint, skin oils, dirt, and fabric softener and creates a sticky film inside the washer. Eventually, that film starts to smell.

You may also notice excessive suds during washing, clothes that feel slightly soapy after the cycle, residue around the door, slime inside the detergent dispenser, or a washer that smells fine immediately after cleaning but becomes musty again quickly.

Always use HE detergent in a high-efficiency washer, and don’t automatically fill detergent to the maximum line. For lightly soiled everyday laundry, you often need considerably less detergent than people expect.

3. A Dirty Detergent Dispenser

The detergent drawer is easy to overlook. Liquid detergent and fabric softener leave behind a surprisingly thick residue over time, and since water enters the dispenser during every wash, the area stays damp and can develop mold.

Remove the drawer if your model allows it and inspect both the drawer and the cavity behind it. Cleaning only the removable tray isn’t always enough — we’ve seen washers where the tray itself looked reasonably clean while the water channels and housing above it were heavily coated in mold and detergent buildup. Use warm water and a brush to clean accessible areas, and check your owner’s manual first since dispenser designs vary considerably between manufacturers.

4. The Washer Isn’t Draining Completely

If your washer smells particularly bad after sitting unused for a day or two, check whether water is remaining inside the machine. A small amount of water remaining internally can become stagnant.

Possible causes include a partially clogged drain pump filter, debris inside the drain pump, a restricted drain hose, a weakening drain pump, an object lodged between the tub and pump, or improper drain hose installation.

If the machine is also draining slowly, displaying a drain error, leaving clothes unusually wet, or making strange noises during the drain cycle, the odor may be a symptom of a drainage problem rather than simply a cleaning issue. This is an important distinction — running five washer-cleaning cycles will not solve a mechanical drainage restriction.

5. Check the Drain Pump Filter

Many front-load washers have a drain pump filter accessible behind a small panel near the bottom front of the machine. This filter can collect coins, hair, lint, small socks, tissue, buttons, pet hair, and other debris.

Once enough material accumulates, dirty water may remain trapped around the filter and pump, and that water can develop an extremely unpleasant odor. If your machine has an accessible filter, consult the manufacturer’s instructions before opening it — there may be a significant amount of water behind the filter, even if the washer appears empty. Prepare towels and a shallow container before removing it. Not every washing machine has a homeowner-accessible drain filter; some models require partial disassembly to reach the pump.

6. Sewage Smell Can Point to the Drain, Not the Washer

There is a big difference between a musty washing machine and one that smells like sewage. If the odor resembles sewer gas, the appliance itself may not be the source.

The washer’s drain hose normally empties into a standpipe connected to your home’s drainage system. Problems with the plumbing can allow odors to travel back toward the washing machine — potential causes include the drain hose inserted too far into the standpipe, an improperly sealed drain connection, a dry or improperly configured plumbing trap, a partially blocked household drain, or plumbing venting problems.

One useful test is to smell around the drain connection behind the washer. If the odor is strongest there rather than inside the drum, you may be dealing with a plumbing issue — and replacing washer components will accomplish nothing if the smell is actually coming from the building’s drainage system.

7. Leaving the Door Closed After Every Wash

A washer should be allowed to dry between cycles. Closing a front-load washer immediately after removing your laundry traps moisture inside the drum and gasket, and over time, mildew develops.

When practical, leave the washer door slightly open after the last load of the day. You can also leave the detergent dispenser partially open so moisture can evaporate. For households with small children or pets, use appropriate caution with an open appliance door.

8. Fabric Softener Can Make the Problem Worse

Fabric softener is another frequent contributor to washer buildup. It’s designed to leave a coating on fabric — unfortunately, it can leave a coating inside your washing machine as well. That residue accumulates in dispensers, hoses, gaskets, the outer tub, and internal water channels.

If your washer develops odor repeatedly despite regular cleaning, try reducing or temporarily eliminating liquid fabric softener. You may be surprised how much difference it makes.

How to Properly Clean a Smelly Washer

If the machine is draining normally and there are no obvious mechanical problems, a thorough cleaning is a good place to start. First, remove all laundry. Clean the door gasket and its folds carefully. Remove and wash the detergent dispenser. Check the drain pump filter if your washer has one that’s designed for customer access.

Then run the washer’s Tub Clean, Self Clean, Clean Washer, or similar maintenance cycle according to the manufacturer’s instructions, using a cleaner approved for washing machines. After the cycle finishes, wipe the drum and gasket dry and leave the door open to ventilate.

If the washer hasn’t been cleaned for years, one cleaning cycle may not remove everything — heavy detergent deposits can exist behind the inner drum where you cannot reach them directly.

Don’t mix cleaning chemicals. Be careful when using household cleaning products inside your washer. In particular, never mix bleach with vinegar, ammonia, or other cleaners, since dangerous gases can be produced. Follow the washer manufacturer’s cleaning instructions rather than combining several chemicals in an attempt to get a stronger cleaning effect.

When Cleaning Doesn’t Fix the Smell

If you thoroughly clean the accessible parts of the washer and the odor returns within a few days, there is probably something else going on. At that point, we would start looking deeper — contaminated water may be sitting inside a drain hose or pump housing, a restriction may be preventing complete drainage, or there may be heavy buildup inside the outer tub that isn’t visible when you look inside the washer.

Watch for other symptoms: the washer drains slowly, water remains in the drum, clothes come out unusually wet, the drain pump runs for a long time, the washer displays drain-related error codes, grinding or humming occurs during draining, water appears underneath the washer, or the sewage smell is strongest behind the appliance. Those clues help separate a maintenance problem from an actual repair issue.

How to Prevent Washing Machine Odors

Once the washer is clean, a few habits can keep the smell from returning. Use the correct amount of HE detergent instead of automatically using the maximum amount. Remove wet laundry soon after the cycle finishes. Leave the door and detergent drawer slightly open when the machine isn’t being used. Clean the door gasket regularly and inspect the drain filter periodically if your model has a serviceable one.

It’s also worth running the manufacturer’s washer-cleaning cycle before you notice an odor rather than waiting until the machine already smells bad.

Frequently Asked Questions