The distinctive smell of sewer gas wafting through your home means something is wrong with the plumbing. Odors can signify a toilet leak or a crack in one of the plumbing vent pipes. Even when all the vent pipes are intact, there's still a good chance that blocked vents are responsible for the odors. When they aren't allowing air into the drains, flowing water can create a vacuum that sucks out the water in the bottom of P-traps meant to keep the gas behind it in the pipes. To fix the problem, you need to clear the vents.
Locate the source of the odor. If it's coming from a toilet, the toilet may need servicing. If you smell the odors at a fixture drain, the vents are probably blocked. Smells coming from the wall signify the need to repair cracked or disconnected vent pipes.
Pull off the toilet if the smells originate there. Do this by turning off the water, draining the tank and unscrewing the toilet bolts with a wrench. Examine the subfloor for moisture damage. If you see any, repair the damaged sections.
Raise the flange if the top is more than 1/2 inch below the surface of the flooring. When the flange is too low, the wax ring can't seal the waste line, and sewer gases can pass through it. Unscrew the flange with a screwdriver, place a flange extender on top of it, and replace the screws to hold the flange and extender to the subfloor. Replace the toilet when you're done.
Clear the vents if the odors originate from a fixture P-trap. You are able to smell the gases at that fixture because the trap has been emptied by a vacuum in the waste line. Confirm this by pouring water down the sink to fill the trap and then flushing the nearest toilet. You'll probably hear sucking and gurgling sounds coming from the fixture.
Climb on the roof with an extension ladder and clear debris from the vent opening. The vent is usually situated just above the main bathroom. It may be blocked by leaves, sticks or even a dead bird.
Pour water down the vent with a garden hose if the opening isn't blocked. The water may clear the obstruction. If not, it overflows from the vent opening.
Insert a sewer auger into the vent and push it down as far as you can if the water overflows. Crank the handle to work the auger through the blockage. When the blockage has been cleared, the water standing in the vent pipe will drain. Spray more water to make sure the vent is open.
Examine the vent pipes in the wall if the smell originates from there. The pipes may be accessible in the attic or basement, but if they are running through the main part of the house, you'll probably have to remove wallboard to get to them.
Re-glue loose joints in the vent pipes with plastic pipe cement. Because vent pipes don't carry water, plumbers often forget to glue them, and odors can seep from unglued joints. Repair cracked or failing fittings by cutting them out with a hacksaw and gluing in replacement pipes and fittings.
Things You Will Need
- Flange extender
- Extension ladder
- Garden hose
- Sewer auger
- Plastic pipe cement
- Prevent debris from falling into your main vent and blocking it by installing a vent cap.
- If leakage and odor from your toilet is extensive, the porcelain may be cracked. If so, the only solution is to replace it.
- When the odor emanates from a fixture that is not used frequently, water may simply have evaporated from the P-trap. Refill the trap and monitor to ensure there is not a leak.
- Sewer odors emanating from your toilet usually signify a leak that can lead to costly floor repairs if allowed to persist.
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