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Is your washer contaminated with mold?

Do your clothes smell terrible no matter how much you wash them or what kind of detergent you use? It’s not likely your clothes. Rather, there could be nasties in your washing machine where it’s probably growing hidden colonies of mold and bacteria.

I’m talking mainly about front-loading washing machines. These are some of the most popular models from the biggest appliance companies[1]. They can harbor a mildew called Erysiphales that makes your clothes and towels stink, and it is tough to get rid of! Because, bacteria lurks in the detergent drawer, rubber seals, and inside the washer drum itself. 

Front load washing machine gasket
Looks clean right? Wrong!
Mold growing in washing machine
Hidden mold growing in washing machine

So, what is the problem with front loaders?  On top-loaders any moist air naturally rises out of the machine and it quickly air dries. But a front-loader is built around a sealed environment, so the water and the moisture stay trapped inside. It’s a very humid environment … and it’s perfect for growing mold.

In front-loader machines too, the rubber door gaskets are designed in a way that always traps moisture and lint materials. This design provides all kinds of places that are hard or impossible to clean or sanitize so inevitably grows mold.

I’ve read that some “experts” claim you just need to leave the appliance door open when not in use. Not true! Others recommend wiping down the door seals in your machine with a 10 percent bleach solution. This might work fine on areas you can see. Unfortunately, there are many folds and weep holes in the seal that make it impossible to thoroughly clean. In the worst cases you may need to replace the entire door seal. This is a labor-intensive task and can be expensive.

The problem is obviously difficult to cure so it is best to prevent. About the best you can do is religiously wash your washing machine once a month from the time it’s new. Then always dry the seal and leave the door open to allow air to circulate. These preventive measures are about the only ways you can keep your washing machine gunk-free and reduce your family’s exposure to mold, germs and infections.

Here’s an effective cleaning process you can follow:

  • Physically clean and remove any soap or lint build-up from the rubber gasketing all around the door. Use a rag and a cleaner that contains bleach or a 1:10 solution of bleach and water, or a 1:1 solution of vinegar and water. This is not easy because there are many folds and holes and they go all the way around the seal.
  • Fill the bleach dispenser with liquid bleach and run the empty washing machine through a cleaning cycle set to “sanitize”. If you’re sensitive to bleach, use baking soda and vinegar instead. Dilute and pour in 1/2 cup of baking soda and 2 cups of distilled white vinegar. 
  • Leave the door or lid open overnight after the cleaning cycle is complete. Make sure the interior has completely dried out before you do your next wash.

Be especially diligent about sanitizing your washer if you live with an elderly relative, a newborn, or if you have an ill family member. Also be wary of public washing machines and machines kept in humid environments such as garages or sheds, since these are the perfect environments for bacteria to thrive. 

Carefully choose wash settings on a case-by-case basis depending on how your clothing became dirty. Regular home laundering will adequately remove normal levels of grease, dirt and other soil. However, if fabrics are contaminated with blood or body fluids, the laundering process should be enhanced with disinfecting solutions such as hydrogen peroxide, bleach, or Borax, and in water that’s at least 160°F. Many newer washers have a “sanitize” setting that will bring the wash water up to these higher temperatures. 

Germs such as E. colisalmonella, and Klebsiella oxytoca can cause pneumonia, skin infections, abdominal cramps, vomiting, and diarrhea, especially in people with compromised immune systems.

Odor causing bacteria will even grow on the clothing itself.  Some, like Micrococci, can give you BO. It likes to live on polyester and wool but is less likely to grow on fleece and viscose. Polyester textiles seem to be a great place to live for Micrococcus, for Enhydrobacter, and for Propionibacterium. These all play an important in creating bad odors from excreted sweat compounds. Another bacteria, Staphylococcus epidermidis grows like mad on both cotton and the polyester textiles used in popular lines of fitness clothes.

Washing machine mold
Hidden mold in your front-load washer
Washing machine mold
Washing machine mold

Want a permanent stink-free solution?  You can get an old fashioned, top-load washing machine. These almost never have the mold problems associated with the front-loading units. Or, there is a cheaper and even more effective germ killer people can employ to keep pathogens and nasties out of their clothes: an old fashion clothes line. One of the best germ killers is simple exposure to the sun. That way you can get rid of your dryer entirely.

Here are some clothes washing tips:

  1. Clean your washing machine: Your washer holds moisture, which leads to bacteria, mildew growth and musty-smelling clothes. Clean and sanitize it monthly.
  2. Do not overload the washer: packing your washer may actually be preventing your clothes from getting clean. Part of what helps clothes get clean is their ability to move around freely and generate friction with each other. Wash smaller loads
  3. Add less detergent: More detergent doesn’t necessarily mean a better clean. In fact, too much detergent can cause your clothes to hold onto dirt and bacteria. Read the clothing label and carefully measure out the detergent.
  4. Rotate hot/cold water settings: If you wash everything in cold water to reduce energy use and hot water bills it may not always be the best choice for getting clothes really clean. For the fabrics that can handle it, washing clothes in the highest water temperature possible can kill odor-causing bacteria and result in a better clean. Always read clothing labels to ensure fabrics are hot-water safe.
  5. Use a deodorizer: A fabric softener doesn’t neutralize odors. The slightly acidic nature of vinegar acts as a great deodorizer. Add one or two tablespoons of vinegar per load to remove odors. It will also prevent fading. 
  6. Take clothes out to dry immediately: While your clothes are sitting in a dark and damp environment, bacteria and mold are setting up shop. Move your clothes into the dryer as soon as the wash is done. If you forget and they’ve been sitting more than two hours, run the clothes through a hot rinse cycle, then immediately dry them.
  7. Hang your clothes in the sun: The UV from the sun will kill most pathogens and the fresh air will make everything smell crisp and clean.

[1] Front loaders have become popular because they claim to be more efficient and they appeal to designers trying to eliminate the space required above the top-loader machines.

Dryer Duct Maintenance Issues

Your dryer duct is probably not something that you think much about. And really you shouldn’t have to as it is permanently built into your home. Unfortunately, clogged dyer ducts are the reason for a large percentage of dryer failures, malfunctions and warranty calls. This happens because your dryer duct needs regular maintenance and is likely not getting any. Most homeowners either don’t know how or the duct has not been installed to allow proper service.

Here’s how the dryer duct works. Your dryer extracts moisture from your clothes during the drying process and pushes this moisture out of the dryer through the duct to the exterior. As this warm moist air passes through the duct, condensation will occur as it makes contact with the cold metal duct walls. See more about washers and dryers here.

If there are lint particles in the moist air, they will stick to and slowly build up on the inside of the moist duct walls. The lint screen in your dryer is designed to keep this lint out of the air stream. That is why it is so important to keep the lint screen clean and from getting damaged or clogged.

Maintaining your dryer duct
Poorly maintained dryer lint screen

Even with proper cleaning of the lint screen, over the course of a year or so enough minute lint particles and dust will build up inside the duct to require service. The maintenance process includes pulling out the dryer, disconnecting the flexible duct connector hose, and then running a brush through the solid dyer duct all the way to the exterior of the home. This removes the lint from the duct walls and clears any blockages allowing the air to flow free again.

Proper ducting material

Proper built-in dyer ducting is made of smooth rigid metal, sealed air tight at all joints and with gentle curves at any bends. This is so cleaning brushes can slide through easily.

Flexible ducting used for this purpose is a code violation. Flex duct is not to be used for any built-in dryer vent ducting except for the final connection to the appliance. Code allows the total dryer ducts to be no longer than 14′ with two elbows.  For vent lengths exceeding 14′ and 2 elbows, a dryer booster fan should be added.

At HPS we occasionally see cheap flexible ducting installed, especially in “flipped” homes. When we see it we recommend immediate replacement so that the duct can be properly maintained down the road. If you have flex in your home, you should replace it with rigid. Your local HVAC contractor can do this for you.

We sometimes also see dryer ducts that terminate in the attic or crawlspace. This is a code violation and it allows moisture and lint to a accumulate in those areas. Elevated moisture and humidity is exactly what mold loves and an open duct is always a nice place for rodents to take up residence. More than once we have found dead rodents in the dyer duct. This is not a good way to have fresh smelling clothes coming from your dryer.

Maintaining your dryer duct
Flexible ducting is NOT for dryers
Maintaining dryer ducts
Dryer duct cleaning kit


Be sure to follow a regular service schedule so you don’t forget to do this. Download your monthly maintenance checklist for this month. Removing the dryer from its location is probably the hardest part of this exercise. Be careful not to damage the floor during the move.

Once out, you can clean the space behind and recover all those lost socks that went missing over the year. Use a flexible brush kit to thoroughly clean the entire length of the duct system from the dryer connection all the way to the termination on the exterior. You can use these brushes with or without a handheld drill. I recommend using the drill combined with a vacuum as shown in the video below. You can make a transition fitting like the one shown in the video for the vacuum and brush to work together from an ABS-Y fitting. Get the brush kit at Amazon here:

Check out this video on how to clean your dryer duct:


Inspect and make sure you have rigid ducting for your dryer, and have it cleaned at least once per year. Make sure you clean the dryer lint screen after every use of the appliance. Inspect the termination at the exterior and make sure the flapper closes securely and there are no shrubs touching. Rodents can use them as ladders into your dryer. Your dryer duct termination should look something like the one below and its should have a damper flap on the inside.  Get one here from Amazon.

Maintaining your dryer duct
Dryer exterior wall termination

www.homepreservationmanual.com is the place to visit if you want information on: maintaining your home; how to improve air quality; ways to improve the real value of your home; what are the best housekeeping services; the problems with handymen services; how to plan and execute home renovation and home improvement projects; tips for spring cleaning; tidying up a messy house; and generally how to be a better homeowner.

Make sure you download your monthly maintenance checklistfor this month.

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Make sure you download your monthly maintenance checklist for this month.

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