To conserve energy and reduce heating costs, many of us have turned to wood burning fireplaces and stoves to supplement the heat we receive from our natural gas furnaces.

However, some homes often are too tight to provide adequate air for the safe operation of open-flame heating systems (fireplaces, wood, oil, propane stoves, natural gas furnaces).

After you weatherize your home, you may need to add a combustion air source to prevent backdrafting. Consult with a qualified heating contractor.

What is back drafting?
Fireplaces require lots of air. If there isn't enough air to satisfy the requirements of a fireplace or wood stove as well as a furnace or water heater all burning at the same time, the fireplace draft can pull harmful combustion products, such as carbon monoxide, from gas appliances back into the room.

The products of combustion must be continuously removed while the fireplace or stove is operating. In fact, any device that removes air from the home can contribute to backdrafting problems, including:

• Kitchen and bathroom exhaust fans;
• Electric and gas clothes dryers;
• Furnaces, and
• Water heaters.

To check for back drafting
Start a fire in the fireplace on a cold day and after a few minutes, touch the vent pipe of the furnace, water heater or any space heater. Use caution, the vent may be very hot.

However, if the vent is cold, your fireplace may be creating a dangerous back draft.

Turn down the thermostat and water heater controls. Let the fireplace burn down (if you have glass doors on the fireplace, close them), and call a heating contractor.