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Washing Machine Smells like Sewage: Causes and Solutions

Your laundry room is where you may spend a great deal of time getting your clothes, sheets, and towels clean. You want your laundry to come out smelling as clean as it looks. If your washing machine smells like sewage, it’s likely the last thing you need. After all, a washing machine that smells like sewage can leads to bad smells in all your clothes and throughout your home.

There are several reasons washing machines develop sewer smells. Admit it, we all know what happens when we leave a load of wet clothes in the washing machine a little too long. It makes for a sewer-smelling washing machine that can waft through the entire house. Gross!

Besides leaving a load in the machine for too long, why else does your washing machine smell like sewage? The short of it is that there is water somewhere in the washing machine that has stagnated and is creating a bad smell, which is referred to as sewage gas.


What is Sewage Gas?

According to the Wisconsin Department of Health Services, “Sewer gas is a complex mixture of toxic and non-toxic gases that can be present at varying levels depending upon the source. It is formed during the decay of household and industrial waste.”

This decay creates a combination of hydrogen sulfide, carbon dioxide, ammonia, and methane. Together, they produce noxious sewer gas. Sewage gas in small quantities is non-toxic, yet it could lead to a gag reflex that we all would like to avoid. Although our washing machines spend all of their time cleaning our clothes, they too can collect dirt and decaying water turning into sewage gases.


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What does sewage gas smell like?

Does your machine smell like rotten eggs? This odor is the telltale sign of sewer gas. Some people smell a combination of mildew, and over-ripe cheese, along with a dash of gasoline. It’s enough to make anyone wrinkle their nose.

Related: Septic Tank Smell in the House? Here’s what you need to do.

What is the cause of the bad smell?

That nasty smell is the hydrogen sulfide rearing its stinky head in your laundry room. When your washing machine smells like sewage there are several reasons that might be causing it.


Front Loaders

A front-load washing machine has a rubber door seal that not only keeps the water from leaking out but when it is closed, it keeps air from circulating in. This sealed environment can manifest into nasty smells in your, clothes, the washing machine, land the laundry room itself. It is worse during the high temperatures of the summer. The higher temperatures combined with drain water make an ideal breeding ground for bacteria. Leaving the door open will allow air to circulate and dry the drum area of your washer.

Top load washers can create the same situation if the lid is left closed. There is no seal around the door making the lid watertight, so the issue isn’t as prevalent as in a front-load machine, but to keep washer smells at bay, leave the lid open when the machine is not in use. If you live in an environment with high humidity this is an especially important step in maintaining a smell-free washing machine and laundry room.


Wet Clothes Left in the Machine

If you are going on vacation, the water left standing in your washing machine drain and drain trap can stagnate. Over time this will start to smell. Maybe you did a load of t-shirts just before leaving for a long trip. Make sure the door of your machine is left open. The bit of moisture still in the drum may cause built-up bacteria and your welcome home will be a sewer smell that will knock you over. If you know your washer will be idle for an extended period of time, drain the hose that is located on the back of your washer and leave the door open.

Wet clothes left in washing machines too long can leave a nasty mildew smell behind. Let’s face it. We have all forgotten a load of clothes and come back a day or two later and found the laundry room wafting with that rotten egg smell. Simply re-wash the load on a quick wash setting. If possible use a hot water setting. Bacteria hates the heat.

A partially clogged drain can collect water in the hose creating bad machine smells. A partially clogged drain will prevent all of the water from passing through the pipe out to the main sewer line creating sewer gases. Maybe the washer drains, but not all the water is gone. Again, you have a machine that smells like sewage.

In extreme cases, there could be a problem with your plumbing such as a cracked drainpipe, or the internal parts may be creating an issue. If simple solutions do not solve the sewage smell, call a professional plumber to further diagnose the issue. The laundry can wait.


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How to Clean the Washing Machine and Get Rid of the Sewage Smells 


Clogged drain pipe or hose

Over time your washing machine’s hose will build up residue left from your laundry detergent. This gunk attracts lint and other normal materials that are washed out of your clothing. Do you know what happened to that bobby pin you left in your pocket? The result? A clogged drain hose. If the machine’s hose is clogged it can be easily cleared with a stiff length of wire (a hanger works well), or a drain snake. Both methods follow the same basic steps.

  1. Pull your washer away from the wall. A washing machine is heavy so be sure to get some help.
  2. Remove the hose from the washing machine drain and from the back of your washing machine. *Note: keep the two ends of the hose above the center to prevent any excess water from pouring out onto the floor. Also, keep a rag handy as the machine itself holds a bit of water.
  3. Empty the hose of any water into the sink.
  4. Straighten a hanger and bend a small U-shaped hook on one end.
  5. Push the hook end in first. When you hit a bit of resistance start turning the hanger to grab the clog.
  6. Continue to pull debris out until the clog is cleared.
  7. Flushing it with a garden hose will help rid it of any bits of dirt or lint the hook missed.
  8. Reattach the machine hose.


Clean the Drum

Regular cleaning will keep your washer smelling fresh. A few simple steps added to your laundry routine will save you from the sewer gas smell. Take the time, at least once per month, to do a deep clean of your washer. Depending on where you live, you may need to adjust the frequency. Areas with high temperatures and humidity (like the southern states along the Gulf coast) may need this type of cleaning once per month. Whereas dry climates (such as those states west of the Rocky Mountains) may only need this deep clean once per year. You know your machine best. Let your nose help you determine the frequency. Keeping a regular schedule will do the trick for staying ahead of the sewer smells.


Materials Needed:

  • Rubber gloves (optional)
  • Old toothbrush
  • Clean sponge
  • Bleach
  • Soda crystals
  • Baking soda
  • Distilled white vinegar


Steps to Rid your Washing Machine of the Sewer Smell

  1. Scrub the soap, bleach, and fabric softener cups (usually located in the washing machine’s drawer) with a toothbrush along with the detergent tubes if you can reach them.
  2. Dilute a small amount of bleach in warm water and wipe the rubber gasket around the drum. Scum and bacteria love to hide here. Clean this seal regularly to prevent buildup.
  3. Bleach is the best at killing bacteria and the washing machine smells. Add four cups of bleach to a top-loading machine or two cups to a front-loader. Run an empty wash cycle on the largest load setting and at a high temperature.
  4. Once the drum is full, pause the cycle for 30 minutes. Some washers come with a “drum clean” setting. Use this if it is available. In front load washers this will rotate the drum at regular intervals to distribute the bleach water.
  5. If your machine doesn’t have an automatic clean cycle, you may want to run an additional rinse cycle to remove any bleach residue.
  6. Wipe down the entire washing machine with a soft damp rag (t-shirts work wonders) and a mild cleaning solution to remove any soap residue, dust, and dirt.


Final Steps to a Clean Drum

One of the best ways to deep clean your washing machine and rid it of detergent build up and unwanted sewage smells is to do a baking soda and vinegar wash. The baking soda will gently scrub away detergent build up and other debris in your machine, while the vinegar acts as an antibacterial and deodorizer.

  1. Mix 1/4 cup baking soda and 1/4 cup water. Add this to the detergent drawer.
  2. Add 4 cups distilled white vinegar to a top load washer or 2 cups vinegar to a front loader.
  3. Run a short wash and rinse cycle with HOT water. You can pause the machine mid-wash to soak the drum.
  4. Use a clean soft rag to wipe any remaining stubborn stains from the drum and gasket.
  5. If there is a remaining vinegar smell run a second rinse.
  6. To add a pleasant fragrance to your washing machine, add a drop or two of essential oil.


Laundry Routines to Keep it Fresh

There are a number of things you can do regularly to keep your washing machine free of sewage smells. A service wash once a month will keep your machine bacteria free, which is the driving force behind bad smells. Most washing machines today come with this option. Check your service guide for more information.

After you have completed the laundry for the week, clean the door seal and rubber gasket. If you seem to have endless loads of clothes, do this weekly. Pick a day of the week (such as Wednesday) and wipe your machine down. The door seal and gasket are ripe for dirt and bacteria build up. A quick wipe down with a mild cleaner or diluted vinegar is all it takes.

Along with leaving the door open on your washing machine also open the detergent drawer if your machine has one. Air circulation is the best for maintaining a smell-free washer.


Soda Crystals to the rescue

There was a time when every household had a stock of soda crystals. After years of chemical usage, people are finding more environmentally friendly ways to maintain a clean household. Soda crystals have found their way back into many laundry rooms. They are one of the best ways to easily clean your washer of detergent buildup, help prevent drain clogs, and stop washing machine smells like sewage and mildew.

These mighty little crystals will not only help keep your drain traps clear but will also help remove limescale. Soda crystals are biodegradable and don’t contain any bleaches, phosphates, or petroleum products. Therefore, it is a good choice if you are concerned about any environmental impacts.

Simply add a cup of soda crystals to an empty hot wash cycle. Making this a part of your regular laundry routine will maintain a clear drain pipe and keep sewer gas from forming.


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Other related washing machine smells:

Washing Machine Smells Like Burning Rubber: Causes and Solutions

Washing Machine Smells Like Rotten Eggs: Causes and Solutions

Washing Machine Smells Worse After Cleaning: Causes and Solutions

Washing Machine Smells Like Mildew? Here’s How to Clean It

Where to Get Quarters For Laundry in Your Area

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