Gas Water Heaters and Other Appliances May Be at Risk of a Sudden and Deadly Flashback Fire

If a flammable substance is used or stored too close to or in an enclosed area with any gas appliance, the pilot light may ignite fumes and cause a flashback fire

Is your home's gas-fueled water heater really safe? In most cases it is, but there is a hidden danger in any gas appliance with a continuously burning pilot light that many homeowners don't learn about until it's too late. Pilot flames can ignite flammable vapors, producing sudden flashback fires that can rupture tanks, scatter embers and ignite surrounding materials.

What Causes Flashback Fires with Gas Appliances?

Flashback fires occur when vapors from gasoline, paint thinners, solvents, aerosol sprays or other flammable liquids accumulate in an enclosed space, often a garage or utility closet—and reach the pilot light’s flame. Once vapor concentration reaches its ignition threshold, the pilot sparks the fumes, sending a flame front backward into the storage area and fuel reservoir.

How Common Are Flashback Fires?

The Consumer Product Safety Commission (CPSC) estimates about 800 flashback incidents annually in the U.S., resulting in around five fatalities and 130 injuries. While these incidents are rare compared to overall residential fires, they can be especially violent. High vapor levels or tightly sealed spaces increase severity.

Safety Precautions for Gas Water Heaters and Other Appliances

Preventing flashbacks is straightforward:

• Never store gasoline, paint, solvents or aerosol cans within 10 feet of a gas appliance.
• Ensure adequate ventilation: open doors or windows when using flammable liquids in a garage.
• Install and annually clean the flame arrestor screen on your water heater or furnace.
• Maintain clearances: keep storage items, cardboard boxes and combustible materials away from all sides of the appliance.
• Test carbon monoxide detectors monthly and replace units older than five years.

Newer Gas Water Heaters Are Safer

Modern gas water heaters sold in North Carolina must include a flame arrestor or flame-failure device under the North Carolina Building Code. These safety features quench flashback flames inside the burner compartment, preventing them from igniting vapors outside the unit. However, flame arrestors can clog. Have a licensed plumber inspect and clean the screen annually, especially in humid coastal regions.

When replacing an old water heater, consider an ENERGY STAR®-rated unit for higher efficiency and lower utility bills. Tankless gas water heaters eliminate standing pilot lights altogether, reducing flashback risk and often qualifying for state and federal tax credits.

North Carolina Resources and Regulations

In North Carolina, gas appliance installers must hold a valid license from the Plumbing Licensing Board. Verify credentials and complaint history at ncplumbingboard.org. For installation standards, consult the North Carolina Residential Code, Section G2409: Appliance Installation, available on the NC Office of State Fire Marshal website.

Piedmont Natural Gas customers can call 1‑800‑752‑7504 for safety guidance. Dominion Energy gas customers should call 1‑866‑366‑4357. For suspected code violations, contact your county building inspections department.

When to Call a Professional

If your pilot light frequently goes out, if you detect a strong gas odor, or if the burner flame is yellow or orange instead of blue, shut off the appliance, ventilate the area and call a licensed technician. Never attempt to repair gas valves or controls yourself, tampering may violate state law and void warranties.