What’s That Smell? Troubleshooting Odors From Your Plumbing

The invention of indoor plumbing transformed the lives of the common man, allowing him to take care of all his personal hygiene needs in the warmth and comfort of the home. Under normal circumstances, the waste water from showers and toilets is whisked away through a series of pipes, leaving both you and your home fresh and clean. Sometimes, however, things go awry. A sudden whiff of foul odor may be your signal that a problem is afoot. There are several causes that you should explore before calling in the professionals.


Clogged drains are the obvious starting point, but they are not the only cause of bad odors.

  • Check all your drains, including the shower, to make sure they are free of clogs. 
  • Remove hair or other buildup with an old coat hanger or drain cleaning tools.
  • Pour baking soda, white vinegar or lemon juice down the drain and flush it with hot water. These will freshen the drain and elimate odors caused by a buildup in the drain.
  • Run an orange or lemon through the garbage disposal to clean the blades and create a fresh, citrus scent in your kitchen.

Sink Traps

If that doesn't solve your problems, you will need to explore further. That means checking the traps on all your sinks to make sure they are working properly. The P trap is located between the drain pipe of the sink and the pipe that carries waste water away from the home. It works by trapping water in the U-shaped pipe to prevent sewer gasses from coming back into the home.

  1. Look under the sink and locate the P-trap.
  2. Place a bucket or disposable container under the trap and loosen the nut on the bottom of the trap.
  3. Catch the water from the trap in the bucket.
  4. Scoop out any slime or residue from the inside of the trap with an old spoon or the wire from a coat hanger.
  5. Remove the entire trap and wash it in hot water if you notice a buildup inside the trap that cannot be easily removed.
  6. Replace the trap and run the cold water down the drain to refill the trap.

Vent Pipe

The plumbing in your home is connected to a vent pipe that is designed to vent sewer gasses from your plumbing system. This pipe is located outside the home. Under normal conditions, it works to keep your home free of nasty odors. Sometimes the pipe gets clogged or fails to function properly. If cleaning the drains and traps to your sinks does not solve your problems with odors, it is time to check the vent pipe.

  1. Check that the vent pipe has a cap on it. Caps prevent small animals or debris from entering the pipe and channel the sewer gasses away from the home. If your vent pipe does not have a cap, wind or other weather conditions may cause a backdraft that prevents the pipe from venting the sewer gasses properly. Replace the cap on the vent pipe or call a plumber to do it for you.
  2. Look inside the pipe for old leaves or rodents who have decided to take up residence. Clear the pipe of any debris to allow the gasses to vent properly.
  3. Observe the location of the vent pipe. While the vent pipe normally extends above the home, yours may be located close to a window where the odors from the pipe are carried inside from sudden gusts of air. if you notice odors on windy days, or when the air is heavy and humid, drift from the vent pipe may be your problem. Close the window or seal any cracks around the frame until a professional can be called to take care of the issue.

Sewer gasses are more than an annoyance. They contain a combination of both toxic and non-toxic gasses that can cause hydrogen sulfide poisoning, asphyxiation or explosions. Fortunately, the odor of sewer gasses is detectable long before the gasses present a health risk, but that doesn't mean you can ignore them. If the odor of rotten eggs continues despite your efforts to correct the problem, call a plumber from a company like Riverside Heating & Plumbing to avoid potential health risks associated with sewer gasses.