Unpleasant odors in your home can be alarming and frustrating when you don’t know where they’re coming from. This can be particularly true when it’s happening in your laundry room, as this is where you go to clean clothes and linens.

Strange sewage smells can be an indication that something is wrong with your laundry room plumbing. It’s important to deal with the issue as soon as you notice it, as leaving the problem unaddressed can cause long-term damage to your plumbing system over time.

If you’ve ever found yourself wondering why your laundry room smells, you may benefit from reading this blog post. We’ll go over some common reasons it may be emitting that dreaded sewage smell, as well as how you can prevent it from happening again.

The cause of laundry room smells

Unpleasant odors can be caused by a variety of things. Fixing a problem starts with identifying its source, so let’s go over some common causes of unwelcome odors.

Vent pipes that have clogged

Vent pipes (also known as vent stacks or plumbing air vents) are connected to your washer’s drain and play a crucial role in regulating airflow to ensure the smooth drainage of waste and water from your home. In simpler terms, they prevent sewer gasses from infiltrating your system, helping to maintain the proper functioning of your home’s drain pipes.

These pipes, however, can become blocked and result in an unpleasant sewer odor that permeates your laundry room.

If you’re noticing a foul smell from the walls surrounding the vent pipe, contact a professional plumber. With their expert assistance, you can confirm the cause and have them break up the clog, as well as fix any damage that might have occurred.

Build-up in drain lines

Another cause for why your laundry room smells like sewage could lie in the build-up of hair, soap scum, lint, and other debris that clogs your system’s drain line. 

A plumber fixing this issue will remove the washer’s drain hose from the pipe and use a snake to clear any blockage.

It’s important to have the professional also check the P-trap (usually located at the bottom of the drain pipe). The p-trap holds a small amount of water to prevent sewage smells from seeping into your home. If it becomes dry, it can lead to a sewer odor lingering.

Fixing this issue entails pouring about a gallon of water through the drain pipe to replenish the p-trap and eliminate any lingering odors.


Leaks from the water fittings, the drain hose of a washer, or the drain pipes can often go unnoticed, with water collecting on the floor underneath and behind the washer. Over time, this pooled water can mix with bacteria, resulting in an unpleasant odor. 

If you discover any signs of a leak under or behind your washer, it’s essential to have a plumber inspect it. They’ll be able to examine and repair any leaks accordingly.

An improperly installed washing machine

If you’ve recently had a new washing machine installed and are wondering why your laundry room smells bad, it’s possible that improper installation is the culprit. Sometimes, installers mistakenly connect the machine to the drain line without a barrier to prevent sewer gas from entering.

If this is indeed the issue, you’ll need to have your washing machine reinstalled and the drain line properly sealed by a professional plumber. This will ensure that your washing machine functions optimally and eliminate any unpleasant odors going forward.

How to prevent your laundry room from smelling like sewage

Prevention is key. Make sure to follow these useful tips:

• Regularly clean and maintain your washer and dryer, including the lint trap and drain line. This will help prevent any build-up of debris that can lead to foul odors

• Avoid using too much detergent, as it can contribute to clogging and build-up in your washer’s drain line. Follow the recommended amount to use on the detergent packaging

• Schedule regular plumbing maintenance to ensure all pipes and vents are functioning properly. This can not only prevent unpleasant smells but also save you from potential costly repairs in the future

• If you do notice a sewage smell, don’t ignore it. Addressing the issue promptly can prevent further damage and inconvenience

Having problems with your plumbing? Contact J. Blanton

There are a variety of reasons why your laundry room possibly smells. Getting to the root of the issue means enlisting the help of a plumber who will be able to fix the problem in a timely manner.


Prevention can help, but there may be times when you notice the issue a little too late. When that happens, you’ll need to seek out a reliable professional. For that, consider J. Blanton. We’ve been operating in the Chicagoland area for over 30 years, providing quality service for any plumbing problems that residents experience.


Get in touch with J. Blanton by calling us or through our contact form!