What Causes Sewer Odors in the House?
Stephens Plumbing
October 9, 2025

Few things are as unpleasant as walking into your home or business and being slapped in the face by a foul sewer odor. Not only is the stench frustrating, but it may also indicate a more serious plumbing issue that requires immediate attention. Our licensed plumbers know just how disruptive sewer odors can be–here’s a closer look at what could be causing the smell and how to get rid of sewer odor in the house.
Dry P-Traps
Every floor drain, shower, and sink in your home has a P-trap, which is a U-shaped pipe that holds water. This water acts as a barrier, preventing sewer gases from rising into your living spaces. If a drain hasn’t been used in a while, the water in the trap can evaporate–leaving nothing to block odors. Dry P-traps are especially common in seasonal properties and guest bathrooms. Run water down unused drains to see if that eliminates sewer odor.
Broken or Cracked Sewer Lines
A damaged or cracked sewer line can allow gases and wastewater to escape into your property. This problem is serious, as it can lead to foundation issues, water damage, and even health hazards if not addressed quickly. Using specialized cameras, our team can inspect your sewer lines to identify damage. From there, we’ll be able to recommend whether repair or replacement is the best option for you.
Clogged or Dirty Vent Pipes
One of the most common causes of sewer odor in the house is a clogged or dirty pipe. That’s because plumbing systems use vent pipes to direct sewer gases outside of your property. When those pipes become clogged with debris, leaves, or even animal nests, gases have nowhere to go but back inside. If you suspect dirty vent pipes are the source of any unpleasant odors, reach out to our team. A licensed technician should always handle cleaning, as it may require working on a roof with specialized safety equipment.
Blocked or Overflowing Sewer System
When the main sewer line becomes blocked or your sewer system is overwhelmed, gases can back up into your property. Signs that this is the culprit of the unpleasant odor include:
- Gurgling noises
- Slow drains
- Sewage backups
A blocked or overflowing system is a plumbing emergency. We offer 24/7 emergency services to stop the problem before it causes extensive damage.
Improperly Installed or Failed Seals
Dealing with sewer odor in bathroom sinks? Seals could be to blame. Plumbing fixtures rely on wax rings and seals to prevent gases from leaking out. However, over time, seals can fail or may have been improperly installed from the start. Replacing a seal is typically a straightforward job for our team, one that can quickly eliminate the smell.
How to Get Rid of Sewer Odor in the House
If you notice sewer smells, we recommend starting with these steps:
- Run water in all drains to refill P-traps
- Check toilets for leaks around the base
- Look for signs of clogged drains or backups
If the odor persists and you can’t spot any visible signs of an issue, it’s time to call in Stephens. We’ll uncover the source of the scent and go over all available solutions.
Let’s Freshen Things Up
Life’s too short to walk around holding your nose. Whether it’s a stubborn smell in your guest bathroom or a serious issue threatening your commercial space, our plumbers can locate the issue, fix the problem, and restore clean, fresh air. Reach out to get started!

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