How do I find the source of sewer gas smell?

Author: Dr. Dan Haag  |  Last update: Wednesday, June 10, 2026

Where is the odor coming from? Check your home's drains, toilets, and plumbing fixtures for any signs of leaks or damage. Look for cracks, loose connections, or broken seals allowing sewer gas to escape. Additionally, inspect your sewer vents on the roof or outside your home for any obstruction or damage.

How to tell where sewer smell is coming from?

To find the source of that stinky smell, turn to the building's plumbing system. Check sinks, drains, toilets, and other plumbing fixtures for obvious signs of damage, leaking, or loose connections. It's also good to check sewer vents and the clean-out drain outside the building.

How do you find the source of gas smell?

An odor of rotten eggs near an appliance is likely associated with natural gas. Look around the walls for stains; if you notice any discoloration, it could signify a gas leak. You can feel the area for any puffiness, which may indicate excessive heat, which is another indication of a gas leak.

Is there a way to detect sewer gas?

Detecting Leaks

The best way to determine the source of the leak is to perform a smoke test. This is done with equipment designed specifically for performing this test and uses inert smoke that is induced into the drain and vent system through a vent or a sewer cleanout.

Why am I smelling sewer gas in my house?

Simple, easily-fixed causes of sewer gas backing into the house are dried-out water traps, missing clean-out caps or plugs, or a failing wax ring around the toilet. Dry water traps: When water traps dry out from lack of use, sewer gas has a clear path into the house.

What to Do If You Smell Sewer Gas

How to detect where a smell is coming from?

If odors seem to be emanating from this part of your home, check the following locations:
  1. Trash Cans. Under counter trash cans are a frequent source of odors. ...
  2. Ovens. Baked-on foods in your oven can cause burning or smoking odors when your oven is in use. ...
  3. Cooktops and Hoods. ...
  4. Disposals. ...
  5. Dishwashers. ...
  6. Refrigerators. ...
  7. Cabinets.

Who do I call for sewer gas smell?

In addition to being unpleasant, sewer gasses, including hydrogen sulfide, are explosive. The best course of action is to get away from the smell and call a local plumber immediately and get the problem taken care of.

Will carbon monoxide detector pick up sewer gas?

No, it does not. Carbon monoxide detectors DO NOT detect sewer gas. These devices are designed to detect only the presence of carbon monoxide, and thus will not pick up on the other gases that are found in a sewer gas mixture.

Is it safe to stay in a house with sewer gas?

Answer: Only under extremely unusual circumstances. Although hydrogen sulfide is a toxic gas, it will not harm people at the concentrations that exist in a house with sewer gas odor problems. Studies have shown that hydrogen sulfide has a depressant effect on the central nervous system in concentrations above 150 ppm.

Is there a device that can detect gas leaks?

The gas leak alarm sensor is like a superhero that can detect butane, methane, and any odd smells lurking around. And the best part? It talks! It's got voice prompt, so it can be like, "Hey, watch out!

Why do I smell gas but can't find a leak?

If you smell gas near an appliance, it may be just a pilot light that has gone out or a burner valve that is open slightly. If you find this problem and can fix it, the problem may be solved. If you smell gas inside: Go to a phone that is not near the smell and call your local gas company right away.

Will a carbon monoxide detector detect gas?

No, carbon monoxide (CO) alarms cannot detect natural gas leaks. They are designed to detect the presence of carbon monoxide, a poisonous gas formed during incomplete combustion of fuels like oil, gas, propane, and wood.

What could be mistaken for gas smell?

Strong smells in the area, like cooking or chemical odors, can mask the smell of natural gas.

How long does it take for sewer gas smell to go away?

If the sewer gas odor was caused by a dry P-trap, the smell should dissipate almost immediately. If you have any plumbing fixtures you rarely use, you can also easily prevent them from smelling like sewer gas by making sure to put some water down the drain every week or two.

Can sewer gas make you sick?

The Dangers of Hydrogen Sulfide, AKA “Sewer Gas”

Prolonged or acute exposure to the gas can cause eye irritation, headache, nausea fatigue, and – in extreme cases – death.

Why does my bathroom smell like sewer but no leak?

A sewer gas smell in the bathroom can be caused by:

evaporation of water in the P-trap piping. broken seal around the toilet in the wax ring or the caulk. A burst pipe. tree's roots have grown into or have caused damage to your sewer pipes.

Is there a sewer gas detector?

Sewer Gas Detectors are also known as Multi gas detector, equipped with H2S, CO, CH4 and O2 sensors. One commonly used version of this is the Senko MGT Sewer Gas Detector. This device is ideal for use as personal detection equipment as it is fitted with all of the ideal sensors needed to monitor sewer gases.

Why does sewer gas smell come and go?

Due to the frequent movement of water and waste through your plumbing system, and the varying use of different drains throughout the day, some issues can fluctuate. This means that you may only notice the symptoms of a problem, like a sewage smell, at certain times of the day or in response to certain action.

How long does it take to recover from sewer gas exposure?

Exposure to lower concentrations can cause eye irritation, a sore throat and cough, shortness of breath and fluid in the lungs. These symptoms usually go away in a few weeks after exposure ends.

What absorbs sewer gas?

Once sewer gas smell is noticeable, there are few easy things you can do to eliminate it from your home. First, open up all your windows to bring fresh outside air in and keep the affected air moving. Next, use vinegar and baking soda to absorb noxious smells.

Is a sewer gas leak an emergency?

While not always an emergency, persistent smells could indicate a sewer gas leak or a backup in the sewer system. Ignoring these smells may lead to more significant problems, so it's essential to schedule an inspection and cast iron pipe lining service as soon as possible.

How to get sewer smell out of house?

How to Remove the Sewer Gas Smell from Your Home
  1. Identifying the source of sewer gas smell. ...
  2. Repair or replace damaged plumbing connections. ...
  3. Check floor drains and new plumbing to remove odor. ...
  4. Clean and deodorize drains. ...
  5. Using odor absorbers for sewer gas smell. ...
  6. Ventilate your home. ...
  7. Call a Professional Help for Sewer Gas Smell.

How much does it cost to fix sewer gas?

Most homeowners end up paying around $150 per linear foot. Since the average cost for replacing a sewer line is between $1,300 and $4,900, this means the average length of repairs is between nine and 33 linear feet.

How to test for sewer gas in house?

A sewer smoke test can conveniently locate the source of the sewer odor, so we can fix the source of the sewer gas leak. Often, the smell from a sewer is traced to irregularly used drains with dried up traps. Sometimes it's the cracking or wearing down of a pipe.

Should I call the fire department if I smell sewer gas?

If they can't be reached, call the local fire department. If it's anything but a very faint smell, evacuate the building and wait for the gas company to give you an all-clear.

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