If you open your washer and catch a musty, sour smell, or you spot black or pink gunk hiding behind the door seal, you’ve got a mold problem. I’ve pulled apart hundreds of machines over the years, and the good news is that learning how to get mold out of washer drums, gaskets, and dispensers is something almost any homeowner can knock out in an afternoon. You don’t need a service call. You need the right supplies, a little patience, and a willingness to get into the crevices most people ignore.
Mold thrives in your washing machine because it offers everything spores love: moisture, warmth, trapped lint, and leftover detergent. Left alone, it spreads, stains your clothes, and makes a laundry room smell like a damp basement. Below I’ll walk you through where mold hides, the differences between machine types, the supplies you need, and a step-by-step cleaning routine that actually solves the problem instead of masking it.
Where Mold Grows Inside a Washer
Mold rarely starts in one spot and stays put. It colonizes the warm, damp pockets that never fully dry out between loads. Knowing where to look saves you from scrubbing the wrong areas and missing the real source of the smell.
- The rubber door gasket: On front-loaders, this is ground zero. The folds of the bellows trap water, hair, coins, and detergent residue, creating a black, slimy film.
- The detergent dispenser drawer: Liquid fabric softener and concentrated detergent leave a sticky coating that grows pink (Serratia bacteria) and black mold within weeks.
- The drum and outer tub: Biofilm builds on the stainless drum and the hidden plastic tub behind it, especially if you wash in cold water.
- The drain pump filter: Located behind a small access panel at the bottom front of most front-loaders, this trap catches lint and standing water.
Run your finger along the inside top edge of the gasket. If it comes away gray or black with a sour odor, that’s your culprit. Address that area aggressively and the rest of the cleaning becomes routine maintenance.
Front-Loader vs. Top-Loader: Why It Matters
The two machine designs mold up for different reasons, and the cleaning approach shifts accordingly.
Front-Loaders
High-efficiency front-loaders use far less water, around 13 to 17 gallons per load versus 30-plus for older top-loaders. That efficiency is great for your water bill but terrible for mold, because less water means more concentrated detergent and less rinsing. The horizontal door also seals tight, and that rubber gasket holds a pool of water at the bottom after every cycle. If you have a front-loader, expect to spend most of your effort on the gasket and the dispenser.
Top-Loaders
Traditional top-loaders breathe better because the lid sits open more often and the drum drains downward. Mold here tends to settle in the fabric softener dispenser, under the agitator cap, and along the rim where the lid meets the tub. High-efficiency top-loaders without a center agitator fall somewhere in between and benefit from the same drum-cleaning routine as front-loaders.
Supplies You’ll Need
You probably have most of this under the sink already. Pick one disinfectant route, bleach or vinegar, and don’t mix them together, because combining bleach with acidic cleaners releases toxic chlorine gas.
- Distilled white vinegar (about 2 cups)
- Baking soda (1 cup)
- Liquid chlorine bleach (3/4 to 1 cup) for tough mold
- An old toothbrush and a stiff nylon scrub brush
- Microfiber cloths or rags you don’t mind tossing
- Rubber gloves and a pair of safety glasses
- A spray bottle for diluted cleaner
- A bucket of warm water
For routine maintenance, vinegar and baking soda handle the job well. For visible black mold that has set into the gasket, a diluted bleach solution (roughly 1/4 cup bleach to 1 quart of water) cuts through it faster. Open a window and run the exhaust fan whenever you use bleach.
Step-by-Step: How to Get Mold out of Washer Parts
Block out about 45 minutes for a deep clean, plus an hour or two for cycle run times. Work top to bottom so debris you knock loose gets rinsed away at the end.
- Put on gloves and glasses. Mold spores and cleaning fumes are no joke. Ventilate the room first.
- Mix your solution. Combine 1/4 cup bleach (or 1 cup vinegar) with 1 quart of warm water in your spray bottle.
- Spray the affected areas. Coat the gasket folds, drum surface, and dispenser. Let it sit for 5 to 10 minutes so it penetrates the biofilm.
- Scrub. Use the toothbrush for tight folds and the larger brush for the drum and tub opening. Work in small sections.
- Wipe clean. Use damp microfiber cloths, rinsing them frequently in your bucket so you’re not just smearing mold around.
- Run a hot cleaning cycle (covered in detail below) to flush the interior plumbing.
Cleaning the Gasket and Dispenser
These two spots cause 90 percent of washer odor complaints, so give them extra attention.
The Gasket
Peel the rubber bellows back gently with one hand and shine a flashlight inside. You’ll likely find a ring of black slime, plus hair, lint, and the occasional sock. Spray your solution into every fold, wait several minutes, then scrub with the toothbrush. Pay attention to the drain holes at the bottom of the seal, they clog easily. Wipe everything dry with a clean cloth when you finish. If the mold has stained the rubber permanently but the seal is still soft and intact, that staining is cosmetic and won’t spread once cleaned.
The Dispenser Drawer
Most dispenser drawers pull all the way out. Look for a release tab or a notch you press while pulling. Soak the drawer in a sink of hot water with a splash of vinegar for 15 minutes, then scrub the corners and the siphon cap with the toothbrush. While the drawer soaks, reach into the empty dispenser cavity and scrub the roof of that compartment, where sticky softener builds a dark crust. Dry both pieces before reinstalling.
Running a Self-Clean or Hot Maintenance Cycle
After the hand scrubbing, you need to disinfect the parts you can’t reach, including the internal hoses and the back of the tub.
If your machine has a dedicated “Tub Clean” or “Self Clean” setting, use it. Add 1 cup of bleach to the dispenser (or 2 cups of vinegar directly into the empty drum) and run the cycle on the hottest setting. No self-clean option? Just select the hottest, largest, longest cycle available and run it empty. For a vinegar clean, pour 2 cups of distilled white vinegar into the drum, run a hot cycle, then sprinkle 1 cup of baking soda into the drum and run a second hot cycle. The acid loosens residue and the baking soda neutralizes odor and gives a gentle scrub.
When the cycle ends, leave the door open and wipe down the gasket and drum once more. The interior should now smell clean rather than sour. Repeat the hot cycle monthly to keep it that way.
How to Prevent Mold from Coming Back
Cleaning solves today’s problem. These habits keep mold from returning, and they cost you almost nothing.
- Leave the door and dispenser drawer cracked open between loads so the interior dries out. This single habit prevents most front-loader mold.
- Wipe the gasket dry after the last load of the day. Thirty seconds with a towel removes the standing water mold needs.
- Use less detergent. Most people use two to three times what HE machines require. Excess soap doesn’t rinse away, it feeds mold. Measure to the line.
- Switch to HE detergent if you run a high-efficiency machine, and skip liquid fabric softener, which leaves the stickiest residue of anything you pour in.
- Remove wet laundry promptly. Clothes sitting in a damp drum for hours seed the whole interior with spores.
- Run a hot maintenance cycle monthly with vinegar or a tub-cleaning tablet.
- Improve laundry room airflow. A dehumidifier or an open window keeps the surrounding humidity down, which slows mold everywhere.
If you’ve scrubbed and disinfected but the smell returns within days, the mold has likely colonized the area behind the drum or inside the drain pump and hoses, places a normal cleaning won’t reach. At that point, pull the pump filter and clean it, and if the odor persists, it may be worth having a technician inspect the tub. For the vast majority of machines, though, the routine above clears the problem and a few simple habits keep your washer, and your clothes, smelling fresh for the long haul.
