Problems With Plumbing Smells

Plumbing runs all through your house, giving you the luxury of being able to wash dishes, bathe and use the restroom facilities without ever leaving the comfort of home. When it’s working well, it is a great thing — but when the smell from the septic or sewer system creeps inside your home, it is suddenly a nuisance. There are several problems that can lead to the presence of plumbing odors inside the home. Most of them are minor and temporary, while some may take some plumbing expertise to fix.

Cracks in Pipes

A dry trap may be the cause of your plumbing odors.

If the rotten egg smell of gas seeping from the sewer or septic system is infiltrating your home regularly and does not seem to go away, then there may be cracked drainpipes in or near your house. This would be the most serious type of problem that could cause plumbing smells. In the event that a drainpipe has ruptured or cracked, the smell from the gasses below that are generated by the waste will likely be present most of the time in your home. The smell may come and go if the damaged line is buried in the yard, but if the broken line is located inside your home, you will likely notice it all the time.

This type of repair will require pipe replacement done by a professional. It could require some demolition, depending on where the cracked or ruptured pipe is located.

Clogged Vent Pipes

The culprit of smelly plumbing in your home may be something quite simple, yet very hard to detect. The pipes that stick up through the roof of your house are intake vents for the plumbing system. When water is sent down the pipes in the house, the gasses and air from the sewage are pushed ahead of it. The air in the pipes needs to be replaced, and it is sucked from the rooftop air through the vent pipes. However, when these vent pipes become clogged with leaves, a bird's nest, a ball or anything else, the blockage can force air to be sucked in from elsewhere. The air will be forced in through various fixtures such as sinks, toilets or other areas.

This, in itself, doesn’t cause the odor, but the traps at the fixtures can. P-traps are P-shaped bends in plumbing that are found beneath sinks, in toilet plumbing and anywhere else you run water down a drain. The shape of the pipe is meant to hold a bit of water to seal off the pipe so the gasses from the sewer system do not come back through the pipes and into the home. If the force of water going down the drain is significant, it can suck the trap dry when the vent pipes are clogged, which immediately allows the gas to escape into the home, according to the National Environmental Service Center website. Running more water into the trap should fix the problem.


Backdrafting is the act of drawing air up from another area using the energy of another source. For plumbing odor purposes, backdrafting refers to the use of an exhaust fan such as the ones found in many bathrooms. While the exhaust fan is supposed to remove odors from a bathroom, it can actually be the cause of more odors. The pressure caused by the turning fan can draw gasses up from the sewage through pipes in the room. This is generally not a problem unless there are dry traps that allow the free flow of gas to enter the room. Making sure the room has adequate fresh air intake is the key to preventing this problem.

About the Author

Lee Morgan is a fiction writer and journalist. His writing has appeared for more than 15 years in many news publications including the "Tennesseean," the "Tampa Tribune," "West Hawaii Today," the "Honolulu Star Bulletin" and the "Dickson Herald," where he was sports editor. He holds a Bachelor of Science in mass communications from Middle Tennessee State University.