Short answer: Leave the house right away without touching light switches, phones, appliances or thermostats, and once you're outside at a safe distance call 911 or National Grid's 24-hour Long Island gas emergency line, 1-800-490-0045. National Grid responds at no charge and makes the situation safe, but if the leak is in the gas piping after your meter, that piping is yours, so a qualified plumber has to repair and pressure test it before National Grid will turn the gas back on.
Right now: get out, then call from outside
National Grid's Long Island safety guidance is the same for any suspected leak, even a faint smell:
- Get out. Everyone leaves the house. Leave windows and doors as they are.
- Don't make a spark. Don't touch light switches, doorbells, phones, appliances or thermostats, don't pull plugs, don't smoke, and put out any open flame.
- Call from a safe place. Once you're outside and away from the house, call 911 or National Grid's gas emergency line for Long Island and the Rockaways, 1-800-490-0045 (24 hours a day). National Grid asks you not to assume a neighbor already called it in.
- Stay out until National Grid tells you it's safe to go back in.
National Grid treats more than a smell as a gas emergency. It also counts hissing, roaring or whistling from gas pipes, a white mist or bubbles in standing water outdoors, dead patches of plants with no other cause, gas to an appliance that won't shut off, abnormally high or low flames or no gas on every appliance, and water continuously leaking from a gas boiler or water heater. National Grid also warns about "odor fade": the rotten-egg odorant can sometimes weaken, so don't wait for a strong smell if you see or hear these other signs.
What National Grid does when it arrives
National Grid's contractor specifications for New York City and Long Island (the Blue Book, Revision 13, July 2025) say every customer gets emergency help at no charge for gas odor reports, pressure problems and other unusual conditions with the gas supply. If the technician finds something unsafe, New York State rules require a warning tag, and National Grid uses three classes:
- Class A: an immediate hazard, usually leaking gas piping or carbon monoxide. The gas is shut off and locked at the meter, or the problem is isolated some other way.
- Class B: an immediate hazard, usually an unsafely installed appliance. The gas is shut off, but not locked at the meter if the hazard can be isolated from the rest of the system.
- Class C: not an immediate hazard but could become one, such as a badly installed flue pipe. The gas is left on, and you're told what needs fixing.
Who owns which part
- National Grid's side: the gas service line, the meter, the regulator and the meter piping stay National Grid property even though they're on your lot. Only National Grid may shut off or turn on the meter, break a lock or seal, or let gas into piping that's been shut off.
- Your side: everything from the outlet of the meter onward, above or below ground, is customer-owned piping. National Grid says maintaining it is the customer's job, including buried lines to things like a pool or hot tub heater, gas grill, generator, outdoor gas light or detached garage. It recommends having buried lines checked periodically by a plumbing and heating contractor or a leak-survey and corrosion expert, and repaired right away if they're unsafe.
So if the leak is at the meter or in the line from the street, National Grid handles it. If it's in your house piping, a fitting, or an appliance connection, you'll need a plumber or heating contractor.
Getting the gas back on after a leak
- Have the piping or appliance repaired by a qualified, licensed contractor. Check the license first with our guide on how to check a plumber's license in Suffolk County, and ask whether the Town of Brookhaven (or your village) needs a plumbing permit for the repair. Our Brookhaven permit guide explains how the town treats plumbing work.
- Ask about Task 87 qualification. Since April 1, 2023, National Grid requires anyone doing certain gas work on Long Island to be Gas Operator Qualified for Northeast Gas Association Covered Task 87, even a licensed master plumber. That covers isolating and purging piping, reconnecting shut-off house piping to live gas, and building or repairing the meter header, meter bar and regulator vent piping. If your repair touches any of that, ask the contractor to confirm they're qualified before work starts.
- Pressure test. National Grid's Long Island table for ordinary low-pressure house piping (up to 14 inches of water column) calls for a test at 3 PSIG held for 30 minutes on air or an inert gas. Ask the contractor to give you the test results in writing.
- Restore service. If only one appliance or one section of piping was shut off (not locked at the meter), the Blue Book lets a licensed, qualified contractor restore gas to it once it's repaired. If the gas was shut off and locked at the meter, you or the contractor must tell National Grid the hazard is fixed and ask National Grid to turn the gas back on. Only National Grid can remove the lock.
- Be home for the visit. National Grid's appointment checklist says an adult (18 or older) must be there the whole time, and the technician needs clear access to the meter and your gas appliances. Long Island gas appointments are handled through National Grid Customer Service, 1-800-930-5003.
Do I need a gas detector or a carbon monoxide detector?
New York's Executive Law § 378 requires an operable carbon monoxide detector in one- and two-family homes that have a fuel-burning appliance (a gas boiler, furnace, water heater or range counts) or an attached garage. New York City has a separate rule requiring natural gas detectors by January 1, 2027, but that is a city rule and doesn't apply in Suffolk County. A plug-in or battery natural gas alarm can still be a useful backup, but National Grid's advice is to act on any smell or sign and never rely only on an alarm.
Digging near a buried gas line
Before you or a contractor dig for a fence, deck, pool or plantings, contact NY811 (call 811 or use newyork-811.com). That marks utility lines on the public side; National Grid notes that buried customer-owned lines, like the one to a pool heater or grill, are yours to know about and maintain.
Sources
- National Grid, Report a Gas Emergency (signs of a leak, what to do, Long Island emergency number)
- National Grid, Gas Safety Newsletter, June 2025 (Long Island) (get out, report, stay out; odor fade; NY811; customer-owned lines)
- National Grid, Pipes on Your Property (Long Island)
- National Grid, Blue Book: Specifications and Requirements for Gas Installations, New York City and Long Island, Revision 13, July 2025 (definitions of customer and customer-owned piping; warning tag classes; sections 3.10 to 3.13; Appendix D pressure test table)
- Plumbing, Heating & Cooling Contractors of Long Island, National Grid Operator Qualification (Covered Task 87, effective April 1, 2023)
- National Grid, Appointment Checklist and Long Island phone numbers
- New York Executive Law § 378(5-a) (carbon monoxide detectors)
- NYC Department of Housing Preservation and Development, Detectors (NYC-only natural gas detector rule)
General safety information checked against National Grid and New York State sources on Nov 1, 2026. In an emergency, follow the instructions of 911 and National Grid over anything on this page.
Common questions
What number do I call if I smell gas on Long Island?
Get outside first, then call 911 or National Grid's 24-hour Long Island gas emergency line, 1-800-490-0045. Don't call from inside the house.
Does National Grid charge to check a gas smell?
No. National Grid's Blue Book says every customer gets emergency assistance at no charge for gas odor reports, pressure problems and other unusual conditions with the gas supply.
Who pays to fix a gas leak inside my house?
Piping after the outlet of the gas meter is customer-owned, so repairs to house piping and appliance connections are the homeowner's, done by a qualified contractor. National Grid owns and fixes the meter, regulator and service line.
National Grid locked my gas meter. How do I get the gas back on?
Have a licensed contractor repair the problem and pressure test the piping, then you or the contractor tell National Grid the hazard is corrected and ask it to restore service. Only National Grid can remove a lock at the meter, and an adult must be home for the visit.
Does my plumber need special qualification for gas work on Long Island?
For some of it. Since April 1, 2023, National Grid requires Gas Operator Qualification for Covered Task 87 work on Long Island, which includes purging piping, reconnecting house piping to live gas, and meter header, meter bar and regulator vent piping. A plumbing license alone isn't enough for that work.
Are natural gas detectors required in Suffolk County homes?
The January 1, 2027 natural gas detector requirement is a New York City rule. Statewide, Executive Law § 378 requires a carbon monoxide detector in one- and two-family homes with fuel-burning appliances or an attached garage.
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