7 Best Gas Leak Detectors, Tested by Home Experts

Our team of product analysts, home improvement experts and engineers drew on five decades of combined experience to identify brands with proven track records for reliability and performance. We then zeroed in on the specific products that you're most likely to find in stores and online.

Our engineers spent many hours reviewing each unit's technical data to ensure it meets various industry standards, including UL certification. To test gas leak detectors, we exposed detectors to various gases to ensure that alarms were triggered quickly and effectively. To assess each unit's usability, we evaluated its ease of set-up, the intuitiveness of any companion apps and how easily it integrates with other smart home products (if applicable).

✔️ Type of gas: It’s important to understand which gases can be detected by the device and which won’t be. Some detectors can identify more than one gas and some can detect smoke. But don’t make the incorrect assumption that a CO detector will also detect a natural gas leak: Unless it specifically says it will, it won’t.

✔️ Power source: Make sure the device has an indicator so you know it’s being powered. Our pros advise testing your installed detectors every month and replacing the batteries at least once a year. Pro tip: Choosing to replace them on New Year’s Day is always a good annual reminder. Also, keep in mind when shopping that some devices are sealed units that must be completely replaced when the battery fails.

✔️ Expiration date: Many units are only designed to function effectively for a certain amount of time (e.g., five years, seven years, 10 years). Make a point of replacing the device in advance of the expiration date.

✔️ UL-Listed: For peace of mind and better assurance of functionality and operational safety, look for a gas leak detector with a UL-Listed certification. This indicates that the unit has been tested by and meets the safety standards of the Underwriter Laboratories, a third-party organization that conducts rigorous independent research and analyzes safety data to develop standards to guide the safe, sustainable commercialization of evolving technologies.

✔️ Sensitivity: The greater the sensitivity, the easier it'll be for your gas leak detector to identify the source of the leak. We recommend looking for adjustable sensors.

✔️ App-based alerts: Some devices can send data via an app to your smartphone, via Wi-Fi or Bluetooth, to let you monitor the situation even if you’re not there.

✔️ Smart home integration: If you already have other smart home gadgets, consider a gas leak detector that's compatible so it can easily integrate into your smart home ecosystem and boost your home security even further.

Gas leak detectors come in various shapes and forms, though you'll commonly find stationary devices installed in homes. Our pros recommend this type for their ease of use, effectiveness and ability to detect a range of gases. To help you choose the right gas leak detector for you, we describe key features and differences among different types ahead:

• Stationary devices: These gas leak detectors are installed either on the ceiling or high up on a wall or in another specific location as directed. They sense toxic gas leaks (like carbon monoxide) or combustible gases (like propane or natural gas); some units also detect smoke. They run continuously and are either battery-powered or hardwired to the home’s electrical system. If the device is plugged into an outlet, it should come equipped with an extension cord so that the sensor can be installed higher up on the wall to detect various gases.
• Handheld probe: These sniffer devices detect combustible explosive gases in the area near the probe and display the concentration of gas on a meter. They can be used as a safety check if you have just installed a gas appliance and you suspect a potential gas leak from the piping. These units don’t run continuously, and cannot sense carbon monoxide and therefore cannot be used in place of carbon monoxide or smoke detectors.
• Spray: A gas leak detector spray is only effective if you manage to spray it on exactly the spot where the potentially explosive gas leak is occurring. It works the same way as spraying soapy water on a tire that's losing air. It's for this reason that our pros caution against using spray gas leak detectors.
• Pens: A gas leak detector pen senses combustible gas. We advise against this type of detector since it has to be very close to the source of the gas leak to detect it, which is extremely dangerous. It also doesn’t detect carbon monoxide and will not operate continuously.

Throughout your home, you may need multiple gas leak detectors, especially if you have more than one bedroom or multiple floors. Though most of the sensors we recommend will operate continuously, usually for years, to alert you if a gas leak is detected, they're not designed to identify the exact source of a leak. Utility companies strongly caution homeowners against searching for the source if they have been alerted to a potential gas leak.

• Follow the manufacturer's instructions on where to put a gas leak detector. Whether the device is plugged into a wall outlet or is battery operated and mounted on a wall or ceiling, detectors must be installed in an optimal location so that they have the best chance of detecting a gas leak and alerting you. For example, you'll install a natural gas (methane) detector near a gas appliance. Since natural gas and carbon monoxide are lighter than air and rise, detectors should be placed higher in a room. Meanwhile, propane is heavier than air and sinks, therefore the sensor should be situated lower.
  
• You may need additional sensors placed strategically around your home. According to the National Fire Protection Agency (NFPA), carbon monoxide detectors should be installed in a central location outside each sleeping area, and on every level of the home as well as other locations where required by applicable laws, codes or standards.
  
• Interconnect your devices. Per the NFPA, for the best protection, you should interconnect all CO alarms throughout the home, so that when one sounds, they all sound.
  
• If you are hard of hearing, some smoke/CO alarms are equipped with a strobe light which turns on when the alarm is triggered. A bed-shaker can be set up to be activated by the alarm to awaken and alert someone who may have removed their hearing aids for the night. The Red Cross has a program to install a limited number of specialized bedside alarms for those who cannot afford them.
  

Here are some of the most common offenders to watch out for when it comes to the air in your home:

• Combustible gases: Natural gas, mostly comprising methane and propane, has an additive called mercaptan that smells like rotten eggs — but if you’re not in the immediate area where the source is, you might not smell that leak until it’s catastrophically too late. Combustible gas detectors use catalytic and infrared sensors, and since propane gas is heavier than air, detectors should be placed low to the ground.
• Toxic gases like carbon monoxide: Exposure to high levels of colorless, odorless carbon monoxide (CO) from a leaking appliance or a vehicle running in an attached garage is harmful, and can be fatal. These gases are lighter than air, so detectors should be placed high in a room to detect potential leaks. Toxic gases are identified by electrochemical and metal oxide semiconductor technologies.
• Radon: While a concentration in your basement or crawl space won't cause your home to explode the way propane or natural gas can, radon is radioactive and is the second leading cause of lung cancer, according to the Environmental Protection Agency (EPA).

✔️ Evacuate the house immediately if you notice that rotten egg smell of a potential combustible gas leak (natural gas or propane), and call your gas company from outside the home. Utility companies advise that if you suspect a gas leak in your home, do not attempt to identify the source of the leak.

✔️ If the carbon monoxide detector sounds, ensure everyone (including pets) is accounted for and outside or in a well-ventilated space, and call the local fire department. Let them advise you when it’s safe to reenter the home.

✔️Avoid turning anything on or off. That goes for light switches, appliances, thermostats and even a doorbell. The action of turning something on or off could cause a spark, which could ignite flammable gasses.

✔️ Do not ventilate the home. Let the fire department or utility company try to identify the source of the leak first.

This roundup was last updated by Timothy Dahl, a contributing writer for Good Housekeeping who has spent the past two decades reviewing home improvement products, tools and household essentials.

Timothy worked closely with Dan DiClerico, who has covered the home improvement market for more than two decades for brands like This Old House and Consumer Reports, before joining the Good Housekeeping Institute in 2022. In his role as director of the Home Improvement & Outdoor Lab, Dan oversees the testing of all outdoor products, collaborating with our team of writers and product analysts.