Sewer Odors


A general plumbing rule of thumb is that every drain needs a trap, and every trap needs a vent. All those traps and drains are designed to prevent sewer gas from entering your home. The vents in your home should channel sewer odor up to the roof, while drain traps create a “water plug” that acts as a barrier stopping sewer odors from coming through the sink drain. If you smell sewer gas in your home, that means either a trap has run dry or a vent line has cracked.

If you notice a foul sewer smell in your house, here are a few possible causes:

  1. You have a water trap under a floor drain, laundry tub or wash basin that has dried out from lack of use. Water in any trap under unused drains will eventually evaporate. That would allow sewer gas to come up through the drain into the room. Solve that problem just by dumping a pitcherful of water into the drain to restore the trap water.

  2. It’s less likely, but the water in the toilet trap also could have evaporated. Weeks of disuse could cause this. Of course, simple flushing will restore that water.

  3. Another culprit for a sewer smell in bathroom could be a bad wax ring seal between the toilet flange and the base of the toilet. This wax ring can occasionally leak, sometimes because of a rocking toilet that has broken the seal. With a leak in this seal, sewer gas will find its way out from under the toilet. If that’s the case, you’ll have to remove the toilet and replace the wax ring.

  4. A more serious prospect for the sewer smell in your house would be a broken or cracked sewer line or even a loose connection joint in the ceiling or buried in a wall. If you’ve addressed the easier possibilities, use your nose to start investigating.

If you questions, give us a call at Richie’s Plumbing.
Call 504-241-1556