Why Does My Sink Smell Like Sewage?

sink smell like sewage

A sink that smells like sewage is not only unpleasant—it can signal underlying plumbing problems that need attention. Identifying the cause early can prevent health hazards, water damage, and costly repairs.

Here are the most common reasons your sink might smell like sewage and what you can do about it.

1. Dry P-Trap

The P-trap is the U-shaped pipe under your sink that holds water to prevent sewer gases from entering your home. If the P-trap dries out—common in sinks that aren’t used often—sewer gases can escape.

Solution:

  • Run water in the sink to refill the P-trap.

  • Pour a small amount of mineral oil into the trap to slow evaporation for sinks used infrequently.

2. Clogged or Dirty Drain

Hair, soap scum, grease, and food particles can accumulate in your drain, creating a foul odor. Bacteria breaking down these materials produce the sewer-like smell.

Solution:

  • Clean the drain with a mixture of baking soda and vinegar followed by hot water.

  • Use a drain snake for deeper blockages.

3. Vent Pipe Issues

Your plumbing system has vent pipes that allow sewer gases to escape outside. If a vent pipe is blocked (by debris, leaves, or even a bird nest), gases can be forced back into your home through your sink.

Solution:

  • Inspect the vent stack on your roof for blockages.

  • A licensed plumber can safely clear vent pipes and restore proper ventilation.

4. Sewer Line Problems

Cracks, leaks, or backups in your sewer line can cause persistent sewage smells in sinks or other fixtures. This is more serious and usually requires professional attention.

Solution:

  • Call a licensed plumber to inspect your sewer line with a camera.

  • Prompt repair or replacement prevents further damage and health risks.

When to Call a Professional

If odors persist after simple fixes or you suspect a sewer line problem, contact a professional plumber. Davis Plumbing & Heating, Inc. provides expert inspection, cleaning, and repair services in Riverside County, Menifee, Perris, and surrounding areas.

Signs you need professional help:

  • Persistent sewage smell despite cleaning drains

  • Multiple sinks or fixtures affected

  • Visible leaks or water damage near plumbing

Final Thoughts

A sink that smells like sewage is more than a nuisance—it’s a warning sign of potential plumbing issues. Addressing the problem quickly ensures a healthy, odor-free home.

📞 Call Davis Plumbing & Heating, Inc. at (951) 657-0393 to inspect and resolve sewer odors in your home today.