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Fix a sewer smell in house

We'll check drain traps, vent pipes, and toilet seals—or tell you when to call a plumber.

Troubleshooting · Home plumbing
15–30 min
What you'll need
  • None
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Steps

Goal: Refill dry traps, check vent pipes, and inspect the toilet seal.

  • Run water in every drain for 30 seconds to refill dry traps.
  • Check that roof vent pipes are not blocked.
  • Good: Smell gone. Bad: Smell persists—check toilet wax ring or call a plumber.

Refill traps

Goal: Ensure all traps have water to block sewer gas.

  • Run water in sinks, tubs, showers, and floor drains. Unused drains dry out.
  • Good: No more smell. Bad: Check vents.

Check vents

Goal: Verify vent pipes are not blocked.

  • Check roof vent pipes for leaves, bird nests, or snow. Clear any blockage.
  • Good: Vents clear. Bad: Check toilet or call a plumber.

When to get help

Call a plumber if:

  • Odors persist after refilling traps and checking vents.
  • You cannot find the source.
  • The toilet wax ring needs replacement.

Verification

  • No sewer odor inside the house.
  • All drains have water in the trap.
  • Vent pipes are clear.

Escalation ladder

Work from the device outward. Stop when the problem is fixed.

  1. Refill traps Run water in all drains to refill dry traps.
  2. Check vents Verify roof vent pipes are not blocked.
  3. Check toilet and cleanout Inspect wax ring and cleanout cap.
  4. Call a plumber Odors persist or source not found—call a plumber.

What to capture if you need help

Before calling support or posting for help, have these ready. It speeds everything up.

  • Which drains were dry
  • Vent pipe condition
  • Toilet seal condition
  • Steps already tried

Did refilling traps fix the smell?

Run water in all drains for 30 seconds. Dry traps are a common cause.

Run water in every drain—sinks, tubs, showers, floor drains—for 30 seconds. Good: smell gone—traps were dry. Bad: smell persists—check vents and toilet seal.

Yes No

You can change your answer later.

Smell is fixed

No more sewer smell. Run water in unused drains weekly to keep traps full.

Done

Are the vent pipes blocked?

Blocked roof vents can cause sewer gas to back up.

Check roof vent pipes for leaves, bird nests, or snow. Clear any blockage. Good: vents clear—smell should improve. Bad: vents clear but smell persists—check toilet wax ring or call a plumber.

Yes No

You can change your answer later.

Is the smell strongest near a toilet?

A broken wax ring can leak sewer gas.

If the smell is strongest near a toilet, the wax ring may be broken. Replacing it requires removing the toilet—call a plumber if you are not comfortable. If the smell is not near a toilet, call a plumber to locate the source.
Question

Is the toilet the source?

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You can change your answer later.

Call a plumber

Call a plumber if odors persist after refilling traps and checking vents, you cannot find the source, or the toilet wax ring needs replacement. A plumber can smoke-test or camera-inspect to locate the leak.

Done

Reviewed by Blackbox Atlas

Frequently asked questions

Why would I smell sewer gas in my house?
Common causes: dry drain traps (no water to block gas), blocked vent pipes, a broken toilet wax ring, or a loose or damaged pipe. Traps and vents are the most common; run water in unused drains and check roof vents.
Can I fix sewer smell myself?
Yes. You can refill dry traps by running water in unused drains. You can check that vent pipes are not blocked. You can inspect the toilet seal. If odors persist, call a plumber to locate the source.
When should I call a plumber for sewer smell?
Call a plumber if: odors persist after refilling traps and checking vents, you cannot find the source, or you suspect a broken pipe or leak. A plumber can smoke-test or camera-inspect to locate the leak.

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