Signs You Have a Gas Leak and What to Do Right Now

Natural gas has almost no smell of its own, so SoCalGas adds a distinctive odor to help you notice a leak (SoCalGas, SoCalGas fact sheet). People often describe it as sulfur or rotten eggs (PG&E). If you smell it, or see or hear other signs of a leak, treat it as an emergency: leaking gas can ignite and cause a fire or explosion.

Carbon monoxide (CO) is a different danger, covered below. It has no smell, and it comes from fuel that is not burning properly, such as a malfunctioning or poorly vented gas appliance, not from the leak itself.

Signs of a Gas Leak

SoCalGas sorts the warning signs into what you smell, hear, and see (SoCalGas, SoCalGas home safety guide):

• Smell: the added odor. Do not rely on smell alone: some people cannot smell it, cooking and other odors can mask it, and it can fade in certain pipe and soil conditions.
• Sound: an unusual hissing, whistling, or roaring sound.
• Sight: a damaged connection to a gas appliance, dirt or water blowing into the air, or a dry patch of grass or dying plants over or near a buried gas line.

If You Smell Gas or Suspect a Leak

These steps follow SoCalGas's instructions, whether the smell is strong or faint:

1. Leave right away. Get everyone out of the building and away from the area. Do not stop to look for the source.
2. Do not create a spark or flame. Do not turn lights, appliances, or switches on or off. Do not smoke, light a match, start a car, or use a phone or anything else that could spark near the leak.
3. Call from a safe distance. Once you are well away from the smell, call SoCalGas at 1-800-427-2200, the line SoCalGas lists for gas odor and safety calls 24 hours a day, 7 days a week (SoCalGas safety notice). Call 911 if the leak could endanger people or property, or if you cannot reach SoCalGas (SoCalGas emergency response).
4. Do not try to fix it. SoCalGas says not to try to stop the leak or repair a damaged pipe or meter. Gas leaking from a plastic pipe can even build up static electricity that ignites it.
5. Stay out until it is cleared. Do not go back inside until SoCalGas or emergency responders say it is safe, even if the smell fades.

What About a Faint Smell Near the Stove or Water Heater?

It is tempting to turn the appliance off and open windows, but SoCalGas's leak steps do not change for a faint smell: leave, do not switch anything on or off, and call from outside. Cal OES notes that even an electric stove can make a spark. A loose fitting or worn connector is still a leak, and finding and fixing it is a job for SoCalGas or a licensed plumber.

Carbon Monoxide: The Danger You Cannot Smell

CO forms when fuel burns without enough oxygen, for example when an appliance is poorly installed or maintained, malfunctions, or does not vent outdoors (SoCalGas). Symptoms SoCalGas lists include sudden flu-like illness, headache, shortness of breath, nausea or vomiting, dizziness, confusion, drowsiness, and a rapid or fluttering heartbeat.

If you suspect CO and do not smell gas, SoCalGas says to turn off the suspected appliance and open windows only if it is safe, get everyone out, call 911 and get medical care if anyone has symptoms, and have the appliance inspected by SoCalGas (1-800-427-2200) or a qualified professional before using it again.

Gas Leak Repair Costs

Gas lines from the meter to your appliances are customer-owned, and maintaining them is your responsibility (SoCalGas safety notice). Once SoCalGas has made the area safe, a licensed plumber handles repairs on your side of the meter. Typical estimated ranges for licensed plumbers in LA and Orange County (not quotes):

Work	Typical estimated range
Leak detection (pressure test and locate the leak)	$150 to $350
Repairing a leaking connection, valve, or fitting	$200 to $600
Replacing a corroded or damaged section of gas line	$500 to $2,000

Gas leak calls are typically billed at emergency rates, and the cost depends on where the leak is, how hard it is to reach, and whether a permit is needed. CSLB's C-36 plumbing classification covers gas piping on the owner's side of the meter, so confirm the contractor holds a current California license. See gas line service and pricing.

Prevention and Preparation

• Install CO alarms. California's Carbon Monoxide Poisoning Prevention Act of 2010 requires an approved CO alarm in homes with a fossil fuel appliance, a fireplace, or an attached garage. SoCalGas describes it as an alarm for each sleeping area and on every level.
• Have gas appliances checked every year by SoCalGas or a qualified professional, as SoCalGas recommends.
• Contact 811 before you dig. Call 811 or visit california811.org at least two business days before digging; the service is free. SoCalGas marks its lines only up to the meter. Lines from the meter to a pool heater, barbecue, or detached building are yours, and a private pipe-locating professional has to mark them (SoCalGas safety notice, SoCalGas home safety guide).
• Never ignore a gas smell, even if it goes away. Call SoCalGas from outside. A false alarm is better than a missed leak.
• Know your gas meter shutoff, but leave first. SoCalGas says to shut off gas at the meter only if you smell gas, hear it escaping, or see other signs of a leak, and only if it is safe. With a 12-inch or larger adjustable wrench, turn the valve on the pipe coming up to the meter a quarter turn so it sits crosswise to the pipe. Keep the wrench with your emergency supplies or next to the valve. Once the gas is off, do not turn it back on yourself; SoCalGas restores service and relights pilots.

The PlumberNearMe.ai safety guide has a short checklist of these steps.

Sources

• SoCalGas: Natural Gas Leaks
• SoCalGas: Natural Gas Safety fact sheet (PDF)
• SoCalGas: Safety FYI insert, 2025 (PDF)
• SoCalGas: Emergency Response Operations Center
• SoCalGas: Shut Off Natural Gas
• SoCalGas: Carbon Monoxide
• SoCalGas: Home Energy and Safety Guide (PDF)
• PG&E: Safety Action Center FAQs
• Cal OES: What to Do After an Earthquake
• CSLB: C-36 Plumbing Contractor