Best Sewer Gas Detector (updated for 2024)

Combustible Gas Detector, Combustibles Meter, Gas Leak Detector, Sewer Gas Detector -

Best Sewer Gas Detector (updated for 2024)

Sewer gas leak detectors are essential tools for detecting the presence of harmful gases like ammonia, methane, and hydrogen sulfide in sewer systems. These detectors are designed to identify sewer odors and gas leaks that can pose significant risks to human health and safety. Sewer gas smells are common in homes, particularly in bathrooms and near drain openings, and can be both annoying and dangerous. Plumbers, inspectors, water works professionals, HVAC technicians, contractors, and maintenance engineers rely on sewer gas detectors to accurately locate and address sewer gas leaks, ensuring a safe and odor-free environment for residents and workers alike.



  • Sewer gas detectors can monitor the presence of gases commonly found in sewer gas.
  • Sewer gas can be harmful and potentially annoying.
  • Sewer gas detectors are inexpensive, less than $99.
  • Sewer gas detectors can be purchased and used by the average homeowner.
  • Slow and steady wins the race, be slow when testing and trying to find your leak.
  • Some high-end sewer gas detectors can be very expensive and inaccessible to homeowners.
  • Gas leak detector is a broad term that may be misleading
  • Homeowners may accidentally purchase a detector that does not monitor the gases of interest in sewer gas.
  • Fixing gas leaks may require the use of a professional. Other methods include smoke testing and acoustic testing.

The Best Sewer Gas Detectors?

The best Sewer Gas Leak Detectors Include: 

What is Sewer Gas?

Sewer gas is composed of:

  • hydrogen sulfide, ammonia, carbon dioxide, and methane.

It is a natural by-product of human waste and becomes a problem for homeowners when there are leaks, clogged vents, and/or broken pipes. Most term this the rotten egg smell in house, found commonly in older sewer plumbing and building.

What is a Sewer Gas Detector?

A Sewer Gas Detector is a electronic handheld device that has a gooseneck with a sensor. The sensor detectors sewer gas coming from your drain in your shower, bathroom or kitchen. The sensor changes electronic signal and sent to the display showing you the gas concentration level detected. Make sure your gas leak detector is reading in the parts per million concentration scale, abbreviated as ppm. Ensure it is NOT showing %LEL, this is not very sensitive.

Why Does My House Smell Like Sewer?

Sewer gas is produced as a result of household and industrial waste. In includes a mixture of several different gases from the decay of such waste. When you smell sewer gas in your home it means you have a leak, the gases are accumulating to the point where your nose can smell it. 

What Causes Sewer Gas In a House?

A typical drain system is meant to vent sewer gas. If there is a blockage in your plumbing system, such as a clogged drain or a blocked vent pipe, sewer gas can build up and seep into your home. This can also happen if your plumbing system is not properly vented, allowing sewer gas to escape into your home instead of being vented outside.

It also means you have standing sewage in your drain lines. In other words, the waste water is not draining adequately, which allows for organic decay. The decay produces gas which should vent to via a drain vent pipe, but due to some blockage or bad plumbing, it is redirected to a opening in your home. This could be a intended opening like a drain opening, or a unintended opening such as a toilet wax connection not sealed, or a drain pipe that is not sealed or some drain pipe open pathway.

Sewer gas is also known as sewage gas, rotten egg smell gas and sometimes professionals refer to it as biogas.

Can Sewer Gas Cause Health Problems?


Sewer gas has the potential to cause both minor and serious health effects, as the Wisconsin Department of Health Services details, including:

  • Hydrogen sulfide poisoning: This poisoning irritates the eyes and respiratory tract and can cause death at high concentrations.
  • Asphyxiation: The presence of methane can suffocate and cause death when the methane displaces large quantities of oxygen.
  • Burns: Flammability of certain gases in sewer gas can cause burns to individuals who encounter these fires.

    Will Sewer Gas Explode?

    Sewer gas does have the potential for creating both fires and explosions due to the presence of certain flammable and unstable gases in the mixture. Gases of particular concern include hydrogen sulfide and methane.

    What is the Rotten Egg Smell (Sulfur Smell) in My House?

    If you smell sulfur in your house, there are two possible explanations and causes for the foul odor.

    First, it could be a sign of a natural gas leak. This can occur in the case of a substantial natural gas leak. The second explanation for this distinctive odor is that it could be a sign of a sewer gas leak-- such gas does contain some toxic gas components including methane and hydrogen sulfide.

    What is another name for a Sewer Gas Leak Detector?

    Another name used for a sewer gas leak detector includes a sewer gas sensor, sewer gas monitor, sewer gas detection equipment, sewer gas sniffer, sewer odor detector and sewage gas detector.

    What Does It Smell Like if You Have a Sewer Gas Leak?

    In most cases, a sewer gas leak will have a strong sulfur smell which can often translate into a smell reminiscent of rotten eggs. This is primarily due to the presence of sulfur in sewer gas through the gaseous component, hydrogen sulfide.

    Does a Gas Leak Detector Find the Sewer Gas Leak?

    The first step to finding the source of the smell of sewer gas in the home is the use of sewer odor detection. This can be accomplished with a sewer gas leak detector, or sometimes referred to as simply a gas leak detector. Other methods include calling in a plumber and he will undertake a smoke test to assess where, exactly, the leak may be in the pipes and also undertake a acoustic leak test.

    The cheapest way for a landlord or homeowner to track down a sewer gas leak is to use a Sewer Gas Leak Detector.

    Is There a Device to Detect Sewer Gas?

    A combustible gas leak detector for sewers is a piece of detecting equipment that can be used in order to monitor the presence of multiple kinds of combustible gases that are commonly found in sewer gas. In most cases, these devices will alert the user to the presence of specific types of gases, such as hydrogen sulfide, but not have a broad "sewer gas" detection as a whole.

    Instead, the user must be equipped with knowledge of which gases are commonly found in the mixture of gases included in sewer gas and deduce from the combustible gas leak detector whether or not those gases are individually present in a given area.

    How Much Does a Sewer Gas Detector Cost?

    A sewer gas detector ranges from $30 to $300. The Forensics Detectors Sewer Gas Leak Detector costs less than $100 and comes in both RED and YELLOW versions.

    How Long Does a Sewer Gas Detector Last?

    A sewer gas detector lasts for over 5 years. 

    Does a Carbon Monoxide Detector Detect 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 My Nose More Sensitive Than a Sewer Gas Detector?

    Yes. The human nose is more sensitive than a ppm type of gas leak detector.

    Your nose can detect down to 0.001ppm. A detect that costs about $100 bucks detects down to about 1ppm.

    The problem however is that the nose changes sensitivity once it smells a rancid smell such as sewer gas in the home. A process called olfactory fatigue reduces its sensitivity, and as such, is not a reliable objective detector.

    So in other words, a sewer gas detector is more effective than the human nose for identifying a sewer leak and a much more objective instrument. But, the initial nose sensitivity is much more sensitive than any gas leak detector on the market.

    My Sewer Gas Detector Does not Detect Anything. Whats going on? 

    To accumulate and detect high levels of sewer gas, a sewer system relies on two key factors.

    Firstly, the sewer system must contain stagnant sewage and organic matter, creating the ideal conditions for bacteria and enzymes to work their decomposition magic. Through this process, gases like methane, ammonia, and hydrogen sulfide are produced.

    Secondly, the sewer system requires poor ventilation. Insufficient airflow allows these "sewer gases" to build up to measurable levels in parts per million (ppm).

    However, some customers may claim that they can smell the gases even when the sewer gas detector registers nothing. In most cases, when there is proper venting, airflow, and access to the outdoors, these gases become diluted, and the typical sewer odor becomes less noticeable. It's important to note that the human nose is incredibly sensitive and can detect gases in parts per billion (ppb), whereas most human-made leak detectors are only designed to detect gases in parts per million (ppm). Thus, the human nose remains a superior detection system for such odors.

    What Gases Does a Gas Leak Detector Recognize?

    Gas leak detectors can recognize a variety of gases, especially if they are used in the broad sense. Combustible gas detectors can recognize combustible gases, as their name suggests. The Forensics Detectors Gas Leak Detector is intended for combustible gases and, as such, can detect combustible gases including the following:

    • Acetone
    • Acetylene
    • Alcohol
    • Ammonia
    • Benzene
    • Butane
    • Ethanol
    • Ethylene
    • Oxide
    • Gasoline
    • Methane
    • Hydrogen
    • Hydrogen Sulfide
    • And more

    Many gas detectors that are marketed as combustible gas detectors are be able to detect the same gases - combustibles. 

    Are Sewer Gases Release from Drains?

    It depends on your drain configuration.

    Sometimes due to sitting sewer water and lack of drain ventilation, sewer gases can accumulate and be release from certain drain openings. In most cases however, if there is venting, airflow, and open access to the outdoor environment, the gases are diluted and the typical sewer smell is not present.

    sewer gas leak detector

    Does Lowes Sell a Sewer Gas Detector?

    Yes, Lowe's sells gas leak detection solution and a digital multimeter with the capabilities to detect a number of combustible gases that are found in sewer gas.

    Does Home Depot Sell a Sewer Gas Detector?

    Yes, Home Depot sells multiple types of combustible gas detectors. Several of these devices have the capability to detect multiple gases found in a sewer gas mixture.

    How Do I Get Rid of Sewer Gas Smell in My House?

    There are several steps that should be taken to remove sewer gas odor from the home. To start, clean the sink overflow, address the toilet by checking the wax ring and caulking the base, remove bacterial growth from drains, check plumbing systems that are not used frequently, check the garbage disposal, and check for any potential leaks in pipes. The last step on this list may require the assistance of a hired professional if the homeowner is uncomfortable with identifying holes on their own.

    sewer gas leak detector

    What is the Main Cause of Sewer Gas Smell in a Home?

     The main causes for sewer gas odor in the home include the following:

    • Leaks
    • Cracked pipes
    • Air vent blockage
    • Drain clogs
    • Dry plumbing
    • Loose toilets
    • Standing wast water in drains
    • Poor plumbing with P-Traps

    Final Words

    A sewer gas detector, also known as a combustible gas detector, sewer odor detector, or sewer gas leak detector, is a crucial tool for identifying the presence of dangerous gases in sewers and homes. These detectors are designed to detect the presence of combustible gases like methane and hydrogen sulfide, which can pose severe health risks, especially with long-term exposure. Homeowners who notice the smell of sulfur in their homes can use sewer gas detectors to test for the presence of sewer gas and take appropriate action. In most cases, sewer gas leaks are caused by aging, defective, or degrading plumbing infrastructure and can be fixed by hiring a professional plumber to locate and repair the leak, ensuring a safe living environment.

      About the Author

      Dr. Kos Galatsis ("Dr.Koz") is the President of FORENSICS DETECTORS, where the company operates from the scenic Palos Verdes Peninsula in Los Angeles, California. He is a subject matter expert on gas sensor technology, gas detectors, gas meters, and gas analyzers. He has been designing, building, manufacturing and testing toxic gas detection systems for over 20 years.

      gas detector expert

      Every day is a blessing for Dr. Koz. He loves to help customers solve their unique problems. Dr. Koz also loves spending time with his wife and his three children going to the beach, grilling burgers, and enjoying the outdoors.

      Read more about Forensics Detectors here.