A sewer smell in your home is more than just unpleasant. In fact, it’s often a warning sign that something in your plumbing system needs attention. Whether the odor smells like rotten eggs or raw sewage, identifying the source early can help prevent health risks, property damage, and costly repairs.
Below, Moyer Plumbing breaks down the most common causes of sewer smells in the home and what you can do about them.
What Does Sewer Gas Smell Like?
Sewer gas typically smells like rotten eggs, caused by hydrogen sulfide released as waste breaks down. If you notice this odor, pay attention to where it’s strongest—your nose is often the best tool for pinpointing the source.
Common Causes of Sewer Smells in the Home
1. Dry or Faulty P-Traps
P-traps are U-shaped pipes under sinks, showers, and floor drains that hold water to block sewer gases. If a drain isn’t used often, the water can evaporate, allowing odors to escape.
Quick fix: Run water for a few minutes to refill the trap. If the smell returns, the trap may be leaking and should be inspected by a plumber.
2. Drain Buildup and Biofilm
Soap, grease, hair, and organic debris can collect inside drains, creating biofilm—a bacteria-filled residue that produces foul odors.
Where it happens: Showers, bathroom sinks, kitchen sinks, and washing machine drains.
Solution: Regular drain cleaning can help, but persistent smells may require professional service.
3. Clogged Drains or Sewer Lines
Slow drainage combined with sewer odors often points to a clog. Left untreated, clogs can worsen and lead to backups.
Warning signs: Gurgling drains, standing water, recurring odors.
Next step: A licensed plumber can safely remove blockages without damaging pipes.
4. Toilet Seal or Wax Ring Issues
A loose or damaged toilet seal can allow sewer gas to leak into your bathroom—even if there’s no visible water leak.
Tip: If the toilet rocks or smells strongest at the base, it may need to be reset with a new wax ring.
5. Vent Pipe Problems
Plumbing vent pipes release sewer gases safely outside. If they’re blocked, cracked, or improperly installed, odors can leak back into your home.
Common causes: Debris, bird nests, or hidden pipe damage.
Best fix: Professional inspection and repair.
6. Water Heater or Water Supply Issues
If the smell only occurs with hot water, bacteria in the water heater may be to blame. If both hot and cold water smell, hydrogen sulfide may be present in the water supply.
Solution: Water heater flushing, temperature adjustments, or water testing.
When to Call Moyer Plumbing About the Sewer Smell in Your House?
If sewer smells persist, worsen, or are accompanied by gurgling drains or backups, it’s time to call a professional. Sewer gas can be hazardous, and major issues—like sewer line damage or backups—require expert care.
At Moyer Plumbing, our experienced team can quickly identify the cause of sewer odors and provide safe, lasting solutions to protect your home and family.
Contact Moyer Plumbing today for professional sewer and drain diagnostics you can trust.