IMPORTANT
What are residential methane detectors?
Residential methane detectors (RMDs) are electronic safety devices. The devices are designed to detect the presence of methane gas in residential buildings. Methane is the primary component of natural gas. RMDs use sensors to detect methane concentrations and trigger alarms to warn building occupants.
This technology gained significant attention due to its potential to prevent accidents and save lives. The National Transportation Safety Board (NTSB) recommends the installation of natural gas alarms. They recommend these alarms to meet the specifications of National Fire Protection Association 715 (NFPA 715) in businesses, residences, and other buildings. The recommended alarms are for places where people congregate that could be affected by a natural gas leak (data.ntsb.gov/carol-main-public/sr-details/P-25-009).
How methane detectors work
RMDs function similarly to smoke or carbon monoxide detectors. They monitor the air for methane. They issue audible alerts to warn building occupants of a potential gas leak. Equipped with advanced sensors, these devices continuously assess the surrounding environment.
The devices activate alarms when methane concentrations exceed safe limits. If the methane level reaches 0.5% by volume in air, the detectors prompt occupants to evacuate the premises and notify emergency services.
Methane detector technology
- Sensor types: Most detectors use semiconductors, infrared, or catalytic bead sensors. These sensors register methane presence.
- Audible and visual alarms: The device emits a loud alarm when it detects elevated methane levels. The alarm may flash warning lights to alert occupants immediately.
- Smart connectivity: Many modern detectors offer connectivity to smartphones, or emergency services. The detectors provide real-time alerts even when you're away from home.
Power sources
RMDs typically employ one of four power source types:
- Plug-in: Requires an electrical outlet; vulnerable to power outages or disconnection.
- Hardwired: A professionally installed alarm with battery backup. It supports integration with other alarms or an Advanced Metering Infrastructure.
- Replaceable batteries: Flexible installation but requires periodic battery replacement.
- Lifetime batteries: Last the device's lifespan without replacement.
Device installation
Installation locations: To maximize safety, install detectors in strategic locations throughout the home.
- Near appliances: Place detectors about 3 to 10 feet away from gas-powered appliances. Install them near appliances such as stoves, ovens, water heaters, and furnaces.
- Basements and utility rooms: Position detectors close to gas lines, meters, and connections. These areas are common sites for gas leaks.
- Bedrooms and living areas: Install at least one detector on each level of the residence. Prioritize installing one near sleeping areas for nighttime protection.
- Garage: Equip your garage with its own detector if it contains a natural gas meter, gas line or gas appliance, or is attached to your home.
Installation tips
- Mount methane detectors on the wall at least a foot below the ceiling, as methane gas rises in the air.
- Mount RMDs away from drafty windows, vents, or forced-air returns, which may interfere with accurate detection.
- The NFPA 715 standard includes requirements for installing RMD devices, but follow the manufacturer instructions for placement, testing, and maintenance.
Maintenance and testing
Proper maintenance is needed to ensure effective operation of methane detectors.
- Weekly testing: Test each detector using the built-in test button to confirm alarms are functioning.
- Battery replacement: Change batteries as recommended by the manufacturer. Or opt for plug-in models with battery backup for added security.
- Sensor lifespan: Sensors may degrade over time. Replace units as directed by the manufacturer.
- Cleaning: Gently dust and wipe detectors to prevent buildup that can block sensors.
- Professional inspection: Consider annual inspections of gas lines and appliances. We recommend inspections by qualified professionals. Professional installation can supplement detector protection.
What to do if your methane detector sounds an alarm
- Do not use anything that could be a source of ignition until you are a safe distance away. Vehicles, cell phones, matches, electric switches, doorbells, and garage door openers might create a spark.
- Alert others, evacuate, and move to an upwind location.
- Do not attempt to cut off the flow of gas—don't squeeze or try to tie off the gas line and stay away from gas line valves.
- Call 9-1-1 to notify first responders.
- Contact PG&E at 1-800-743-5000.
Install methane detectors according to manufacturer instructions. The device box includes instructions in the accompanying installation manual.
The number of detectors needed is the customer's choice. PG&E has an ongoing pilot project that provides devices based on the location of indoor meters/piping inside a building or structure at the customer address. Purchase detectors for other areas of the building where gas appliances are in use. Additional detectors are at the customer's expense.
While modern detectors are highly reliable, a false alarm can occur due to:
- Exposure to certain cleaning agents, aerosol sprays, or humidity.
- Improper placement or mounting.
- Malfunction or expired sensors.
If you suspect a false alarm, ventilate the area and consult the detector manual. Always err on the side of caution and treat every alarm as a genuine warning.
Replace the detector when the End-of-Service-Life (or EOL) Alert activates on your device. When this happens, the Trouble indicator light on the device will begin to blink twice every 10 seconds. The audible alert will beep twice and say "please replace detector" once every minute. This will occur approximately 10 years after device installation.
If at any time your methane detector alarm sounds or if you ever smell or hear a natural gas leak you should:
- Evacuate immediately and take others with you.
- Do not do anything else that could create a spark or flame and cause the gas to ignite or explode. For instance, do not use a phone; light a match; turn on or off lights, flashlights, or appliances; or start a car.
- Call 9-1-1 and once you are safely outside the premises, contact PG&E at 1-800-743-5000.
- Do not re-enter the premises until told it is safe to do so by authorities.
In the event of a gas leak, you may smell natural gas. You may smell gas even before activating the natural gas detector alarm. Whether or not the unit's alarm is sounding, if you smell gas, act fast. Report the leak once you are safe outside.
The natural gas detector was designed to be as low maintenance as possible. If the unit begins to sound its low battery signal, contact the device manufacturer. They can help you replace the old battery. A single intermittent chirp sound means the battery is low. These batteries are not available in stores.
Clean the unit once a month by gently dusting and wiping the outside of the unit. Do not use water or cleaning solutions on the unit.
Yes. An internal battery powers the unit. The natural gas detector should continue to function during a power outage.
No. The natural gas detector will only detect the presence of natural gas. It will detect natural gas in the area where the unit is installed. It will not detect fire, heat, smoke, or the presence of any other gases, including carbon monoxide (CO).
No. The natural gas detector will only monitor the air in the area where the unit is installed.
Natural gas leaks could be present in other areas and/or on other floors of your home or building without reaching the natural gas detector. As such, the unit's alarm may not sound in the event of a natural gas leak in a different part of your home or building. Doors or other obstructions may also affect the rate at which natural gas reaches the natural gas detector. You should install separate gas detectors as needed in other areas of your home where natural gas appliances are used.
No. The natural gas detector alarm may not be heard in all rooms or situations. Your natural gas detector is installed in a limited area of your home or building. This includes areas like the garage, for example. If there is a natural gas leak, people sleeping or awake in other rooms or on other floors may not hear the alarm. People may not hear the alarm if the sound is at a distance and/or blocked by closed doors. They may not hear the alarm if blocked by other sound obstructions. Noise from traffic, stereos, radios, televisions, air conditioners, appliances, or other sources may interfere with hearing the alarm. The unit's alarm is not intended for people who are hearing impaired.
Related information
Contact us
For general questions, call our Customer Service Center at 1-877-660-6789.
Safety resources
At PG&E, nothing is more important than safety.