Checking gas burners for leaks

Keep your family and home safe by paying attention to your gas furnace or water heater. Here are tips to check for leaks in a gas burner.

• A gas-powered furnace or water heater needs air to properly exhaust, and a house that's too airtight prevents it from getting the amount it requires. This leads to back drafting, a dangerous condition in which flue gases are sucked down the furnace or chimney, allowing carbon monoxide to linger indoors. Carbon monoxide poisoning can be fatal.
• To test, close all windows and doors and your fireplace damper, and turn on all household exhaust fans (such as those in your kitchen over the stove, in the bathrooms, etc.)
• Power up the furnace, water heater and any other vented gas appliances.
• Stand by for 10 minutes to allow drafts to stabilize, then head to the furnace and hold an incense stick (a lit match also works) below the air intake on the burner draft hood. If the resulting smoke is pulled up into the hood, you've got enough fresh air for safe operation; if the smoke blows away from the hood or the match is extinguished, back drafting is in effect. Call your utility company immediately.

•  If you smell a gas leak, shut off the main gas valve, extinguish any open flames, and get out of the house right away.
• Do not try to relight the pilot, make any other adjustments to the furnace, operate electrical switches, or even use the phone.
• Leave the door open behind you as you exit and call your gas company or the fire department from a neighbour's house. Remain outside until the dispatched professional has assessed and corrected the problem and given you permission to reenter your home. Know the location of your gas shutoff valves.
• The main valve is usually located near the gas meter — you'll need a wrench to turn it off. You should know where the manual shutoff valve is for each gas fixture in your house. To shut off a manual valve, turn its handle until it's perpendicular to the pipe.

• To operate efficiently, a gas burner requires the correct gas-to-air balance. You can tell if the balance is correct by looking at the colour of the burner's flame.
• If your burner isn't getting enough air: yellow flame tip; lazy inner flame.
• If your burner is getting too much air: blue flame with a sharp outline and a hard-edged inner flame.
• If your burner has just the right gas-air balance: mostly blue, soft-edged flame with a blue-green inner flame.