You open the washing machine door expecting fresh scents, but instead, you get a whiff of mildew. If your clothes are coming out smelling funkier than when they went in, your machine is likely harboring bacteria, mold, and built-up grime.
Even though water and soap run through it constantly, washing machines are not self-cleaning. In fact, the dark, damp environment is a perfect breeding ground for germs.
To keep your laundry smelling fresh, you need to know how to disinfect a washing machine properly. Whether you prefer the heavy-hitting power of bleach or a natural vinegar solution, we have the steps you need to banish the bacteria.
Key Takeaways
- Deep clean your washing machine monthly to kill bacteria and prevent biofilm buildup.
- Use chlorine bleach for the strongest disinfection, specifically for killing mold spores.
- Use white vinegar and baking soda for a non-toxic, effective descaling and deodorizing clean.
- Always leave the washer door open between cycles to let the drum dry and prevent mold growth.
Why Is My Washing Machine So Dirty?
It seems counterintuitive that a machine designed to clean things would get so dirty itself. However, soap scum, minerals from hard water, and body oils from your clothes don’t always wash away completely. Over time, these elements combine to form a sludge-like layer known as biofilm.
Biofilm is sticky and traps bacteria. If you use cold water cycles exclusively, you rarely get the water hot enough to dissolve this residue or kill the germs living in it.
Additionally, modern high-efficiency (HE) machines use less water. If you use fabric softener or too much detergent, the machine cannot rinse it all away. This excess residue sits in the drum, hoses, and gaskets, creating a feast for mold.
Finally, mold thrives in dark, humid environments. If you close the washer door immediately after a cycle, you trap moisture inside, inviting mildew to move in. To fix this, you need to deep clean your machine once a month.
How to Disinfect a Washing Machine
There are two primary ways to deep clean your washer. The method you choose depends on your cleaning philosophy and the severity of the mess.
Option 1: Bleach. This is the nuclear option. Bleach is the most effective agent for killing viruses, bacteria, and mold spores. If you can see visible black mold, start here.
Option 2: Vinegar and Baking Soda. This is the non-toxic route. The acidity of the vinegar cuts through soap scum and mineral deposits (scale), while baking soda scrubs and deodorizes. This is excellent for maintenance cleaning.
- Time: 1-2 hours
- Difficulty: Easy
Method 1: With Bleach
If you are dealing with sickness in the house or visible mold, bleach is your best friend.
What You’ll Need:
- Chlorine bleach (e.g., Clorox)
- Scrubbing brush or old toothbrush
- Measuring cup
- Rubber gloves
- Protective mask (optional but recommended)
- Microfiber cloths
1. Clean the Gaskets and Door First
Put on your rubber gloves. Bleach is caustic, so protect your skin. Mix a solution of ¼ cup chlorine bleach and 4 cups of warm water.
Dip your brush or cloth into the solution and scrub the “trap” areas. On a front loader, this is the rubber gasket (pull back the folds to get the gunk hiding inside). On a top loader, scrub around the lid and the rim of the drum.
2. Scrub the Dispenser Drawer
Pull out the detergent drawer. If it is removable, take it to the sink and scrub it with your bleach solution to remove sticky fabric softener residue. If it isn’t removable, wipe it out thoroughly with your cloth.
3. Run a Hot Cycle With Bleach
Set your washing machine to its hottest temperature setting and largest load size. If you have a “Sanitize” or “Tub Clean” cycle, use that.
Pour 1 cup of chlorine bleach directly into the empty drum (for top loaders) or into the bleach dispenser (for front loaders). Do not add clothes. Start the cycle and let it run. The hot water and bleach combo will kill germs hiding in the internal hoses and drum.
4. Wipe the Exterior
While the machine runs, use a damp cloth with a little all-purpose cleaner or a very dilute bleach solution to wipe down the knobs, buttons, and exterior of the machine.
5. The Rinse Cycle
Once the cleaning cycle finishes, you want to ensure no bleach residue remains that could spot your next load of laundry. Run a second “Rinse & Spin” cycle with just water. Once finished, leave the door open to air dry.
Method 2: With Vinegar and Baking Soda
This natural combo is fantastic for removing smells and breaking down calcium buildup from hard water.
What You’ll Need:
- 4 cups of distilled white vinegar
- 1/2 cup of baking soda
- Scrubbing brush
- Microfiber cloths
- Rubber gloves
1. Create a Paste and Scrub
Mix a small amount of baking soda with a splash of water to make a paste. Use your scrub brush to clean the detergent drawer and the inside of the door. This abrasive paste helps scour away hardened detergent.
Next, wipe down the rubber gaskets with plain white vinegar. The acid helps cut through mildew slime.
2. Load the Machine
Set your washer to the hottest water setting and the longest cycle available.
For Front Loaders: Pour the white vinegar into the detergent dispenser. Pour the baking soda directly into the drum.
For Top Loaders: Let the washer fill with hot water. As it fills, pour in the 4 cups of vinegar and 1/2 cup of baking soda. Let the machine agitate for a minute to mix it up, then pause the cycle. Let the mixture soak in the drum for one hour to break down the grime.
3. Run the Cycle
After the soak (for top loaders) or immediately (for front loaders), let the cycle run to completion. The reaction between the soda and vinegar, combined with the hot water, flushes out the system.
4. Clean the Exterior
While the machine cleans itself, wipe down the outside with a cloth dampened with vinegar. It leaves a streak-free shine on chrome and glass.
5. Final Wipe Down
Vinegar can have a strong scent. If your machine smells like a salad dressing factory, run a quick rinse cycle with hot water. Finally, wipe the inside of the drum dry with a clean cloth.
Sanitizing Front Load Vs. Top Load Washers
While the chemicals are the same, the mechanics differ between the two machine types.
Top Load Considerations
Top loaders have a major advantage: gravity. You can pause the cycle and let the drum sit full of hot water and cleaning solution. This “soak method” is impossible in front loaders because the water drains if the door opens, or the water level is too low to soak the whole drum.
However, top loaders often have an agitator in the center. You must scrub the underside of the agitator fins, as debris often gets trapped there.
Front Load Considerations
Front loaders are notorious for mold because of the watertight rubber seal at the door. Water pools in the bottom of this gasket, creating a slime trap.
If your gasket has black mold spots that scrubbing won’t remove, try the “soak” trick. Soak microfiber cloths in white vinegar or hydrogen peroxide and pack them into the folds of the seal. Leave them there for an hour. The prolonged contact helps kill the mold in the washing machine gasket.
How to Prevent Mold Growth
Prevention is easier than scrubbing black gunk out of a rubber seal. Follow these habits to keep your machine sanitary:
- Leave the door ajar: This is the golden rule. After every load, leave the door or lid open to let the moisture evaporate.
- Wipe the seal: Keep an old towel nearby and quickly wipe the water out of the rubber gasket after your final load of the day.
- Don’t let wet clothes sit: Transfer wet laundry to the dryer or clothesline immediately. Wet clothes left in a washer for hours will start to smell sour and encourage bacterial growth.
- Use HE detergent correctly: If you have a High-Efficiency machine, use HE detergent and don’t use too much. Excess soap creates the scum that mold feeds on.
Bonus: How Do You Sanitize a Dryer?
You’ve cleaned the washer, but throwing clean clothes into a dirty dryer defeats the purpose. Here is how to refresh it:
- Clean the trap: Pull out the lint trap and wash the mesh with warm, soapy water. Allow it to air dry completely before replacing it.
- Sanitize the drum: Mix a solution of warm water and a small amount of bleach (or vinegar, if you prefer, but never mix the two). Dip a cloth in the solution, wring it out well so it’s damp not dripping, and wipe the entire interior drum and door.
- Rinse: Wipe the drum again with a cloth dampened only with plain water to remove chemical residue.
- Dry the dryer: Toss in a few old towels and run the dryer on high heat for 10-15 minutes. This ensures the drum is dry and any remaining bacteria are zapped by the heat.
FAQs
How Often Should You Clean Your Washing Machine?
You should perform a maintenance clean once a month. However, if you wash heavily soiled items like cloth diapers or muddy sports gear frequently, you may want to run a sanitize cycle every two weeks.
Is Bleach or Vinegar Better to Clean a Washing Machine?
It depends on the goal. Bleach is superior for killing mold, viruses, and bacteria. Vinegar is better for removing hard water scale, soap scum buildup, and neutralizing odors without using harsh chemicals.
Can I Mix Vinegar and Bleach to Clean My Washer?
No, you must never mix bleach and vinegar. Combining these two creates chlorine gas, which is toxic and can cause severe respiratory issues or chemical burns. Use one or the other, but never both in the same cleaning session.
What Temperature Kills Bacteria In a Washing Machine?
To effectively kill bacteria and dust mites, the water temperature needs to be at least 140°F (60°C). Most “Sanitize” or “Hot” settings on modern washers are designed to reach this threshold.
Is it Safe to Put Hydrogen Peroxide In the Washing Machine?
Yes, hydrogen peroxide is a safe alternative to bleach. It disinfects and brightens without the harsh fumes. You can add one cup of 3% hydrogen peroxide to the drum and run a hot cycle to sanitize the machine.
Why Does My Washing Machine Still Smell After Cleaning It?
If smells persist, the mold may be hidden deeper in the machine. Check the drain pump filter (usually a small door at the bottom front of the machine) for trapped debris. Also, inspect the drain hose for blockages or trapped stagnant water.
Fresh and Clean
Knowing how to disinfect a washing machine is the key to truly clean laundry. Whether you choose the bleach method to blast away mold or the vinegar method to descale and deodorize, your nose (and your clothes) will thank you.
Make this a monthly habit, and remember to keep that door open between washes. It’s a small step that makes a huge difference in preventing that funky mildew smell from returning.
