When a natural gas system operates correctly, it burns cleanly with a blue flame, producing heat, water vapor and carbon dioxide, and is the cleanest-burning fossil fuel available. But if the gas isn’t burning properly, or there’s a mechanical failure, the system could produce potentially lethal carbon monoxide, an odorless, poisonous gas.

In the case of home gas appliances, carbon monoxide is caused by incomplete combustion due to improper installation, poor maintenance, or other appliance misuse or failure. The presence of carbon monoxide is indicated by a yellow flame, combustion smells, or soot around the furnace or water heater. People in your home who are exposed to carbon monoxide might feel lethargic, out of breath, dizzy, nauseous or have headaches.

Building codes require that a carbon monoxide detector be placed on every level of a home.  Ideally, they should be placed near a bedroom or in an adjacent hallway.


If You Suspect Carbon Monoxide Exposure
  • Get fresh air immediately.
  • Call 911 or an emergency provider.
  • Don’t use the suspected gas appliance until it has been inspected, serviced and determined to be safe by a licensed heating contractor.

What to Do to Prevent CO Build-Up in Your Home
  • Make sure appliances are installed according to manufacturers’ instructions and local building codes.
  • Have the heating system, including chimneys and vents, inspected and serviced annually by a licensed heating or plumbing contractor.
  • Never burn charcoal inside a home, garage, vehicle or tent.
  • Install a CO detector/alarm on every level of your home.
  • Never use portable, fuel-burning camping equipment such as a propane/butane stove inside a home, garage, vehicle or tent.
  • Never leave a car running in an attached garage, even with the garage door open.
  • Never use gas appliances for heating your home, such as ranges, ovens or clothes dryers.
  • Do not use gasoline-powered tools or engines indoors.
  • Vacuum around burner compartments, and inspect and replace furnace filters on forced-air units or central heating systems according to manufacturer instructions.
  • Never store anything near a gas appliance that might interfere with normal appliance airflow.
  • Make sure the damper is open when using your gas fireplace.