Why Your Washing Machine Smells Like Sewage or Rotten Eggs

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Bad smells coming from your washing machine are not only not welcome but can sometimes be a sign that something is wrong.

If you’ve been noticing a rotten egg or even a sewer smell coming from your washing machine, it’s time to investigate. Not only is it unpleasant but you could be dealing with something potentially harmful to you and your family.

Different smells are caused by different things. So you need to figure out what you’re dealing with before you can solve it.

Rotten Eggs Smell from a Washing Machine

For a rotten egg smell, it could be one of two things. The most likely is bacteria growing in your washer because of built-up dirt, mildew and mold, lint, and/or soap.

If you don’t regularly clean your washing machine, these things build up on, under, or inside the rubber seal and in the crevices of the drum. And sometimes with front-loading washing machines, something small like a sock or a wash cloth gets trapped behind the seal. The trapped item then stays wet and inevitably mildew and mold and bacteria grow.

Another possibility but not as common is a natural gas leak. Natural gas is odorless so the utility companies add sulfur which gives it that rotten egg smell so it’s detectable when there is a leak. If you do suspect a natural gas leak, call your gas company right away.

Fixing a rotten egg smell coming from your washing machine:

This one requires a little elbow grease.

First, for a front-load washer, pull back the rubber seal and check for anything that might have gotten trapped. Then you want to clean the seal. Use a rag and a solution of one part vinegar and one part water. (You can also use bleach instead of vinegar if you prefer) and clean the built up soap scum, mold, and debris.

Then run the machine on the hottest and largest setting. For front-load washers, add ⅓ cup of baking soda to the drum and one cup of distilled white vinegar to the detergent tray. For a top-loading machine, add half a cup of baking soda and 2 cups of distilled white vinegar when it is half full.

Let the cycle finish.

Prevent smells in the future by keeping the washer door open so it can dry. Also wipe dry the machine after each use, especially behind the rubber seal on a front loading machine. And periodically clean your washing machine per the manufacturer’s instructions.

Sewage Smell from a Washing Machine

If a sewer smell is coming from the washing machine itself, washing it per the manufacturer’s instructions and getting in there and wiping down and in between crevices with a vinegar/water solution should get rid of the smell.

If you’ve cleaned the machine and there’s still a sewage smell, it might be coming from the sewer.

To check, pull your machine from the wall and remove the drain pipe out of the standing pipe. If you can smell sewage coming from the standing pipe, there are three main culprits to check for.

Dried Out or Improperly Installed P-trap

There’s a p-trap for every drain in your home for two reasons. One, it traps debris so it can’t get too far into your system and cause a clog. It’s a lot easier to clean out a p-trap than it is to find and fix a clog under the slab.

And two, it also traps sewer gasses from your underground sewer pipes. There is always a little bit of standing water in a p-trap. And this water serves as a barrier preventing sewer gasses from leaking into your house through the drain.

If the p-trap for your washing machine is dry, it can’t trap the gasses and your washing machine/laundry room will smell like sewer. And the same is true if the p-trap or the drain hose connecting the machine to the p-trap was not correctly installed.

The Fix: Pour about a gallon of water down the pipe. If you’re dealing with a dry p-trap, this should fix it. If you still smell sewage, call a plumber to make sure it and your drain pipe have been properly installed.

How to Clean Clogged Washing Machine Drain Pipe

If lint, hair, soap, or dirt create a partial stoppage in the line, eventually bacteria grows on the stoppage and you have a sewer smell on your hands. Left unattended, this stoppage will build on itself causing more odors and possible backups.

The Fix: A sewer machine should clear this up. Sewer machines can be dangerous if you don’t know how to use one, so we recommend you call a plumber to do the job.

How to Clean a Clogged Vent Pipe

You could also have a clogged vent pipe.

Just like the other pipes in your home, the standing pipe for your washing machine also has a vent pipe. Vent pipes allow air to enter the system so water can flow through them and for sewer gasses to escape out of your house, usually through the roof.

So if this pipe is clogged, sewer gasses have nowhere to go but back into your home.

The Fix: If it’s safe, you can get up on the roof and shine a flashlight down the vent pipe. Look for leaves, bird’s nests, or anything that might be preventing sewer gasses from escaping the pipe. If it’s easy to pull out, go ahead. If not, call someone with the proper training and tools to do the job for you.

Call In-House

It’s impossible to cover every potential scenario in a single blog post. More often than not, the above causes will be the problem of a sewer or a rotten egg smell coming from your washing machine.

If it’s as simple as cleaning your washing machine, make sure you prevent future smells by regularly cleaning the machine. Also leave the door or lid open to allow it to dry. If you have little ones or pets and can’t keep it open, there are products you can buy from a hardware store or online that will secure the door while still leaving it slightly ajar.

But if you can’t figure it out or have questions, you can always give us a call at 972-494-1750 or email service@inhouseplumbingcompany.com.


In-House Plumbing Company

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Say goodbye to water or sewer leak issues, especially ones under your foundation, by putting our plumbing company to work for you. We offer timely, sensible solutions and restore peace of mind without significantly affecting your property or budget. Contact In-House Plumbing Company today to schedule an appointment.