When gas and oil burn in vented heating systems, the dangerous fumes that are the by-products of combustion - including carbon monoxide - are released into the chimney through a connector pipe. Funneling these fumes out of the living area is the primary purpose of a chimney. In addition to carrying off toxic gases, chimneys also create the draft (flow of air) that provides the proper air and fuel mixture for efficient operation of the heating appliance. Unfortunately, many chimneys in daily use in homes throughout the country either are improperly sized or have conditions that make them unable to perform their intended function.

GAS.

Natural gas is a clean-burning fuel, but today's high-efficiency gas boilers pose special problems. The fumes they produce are cooler and contain high levels of water vapor, which cause more condensation than older models. Since these vapors also contain chlorides picked up from house-supplied combustion air, the flues are subjected to more corrosive conditions than before and can quickly deteriorate or plug up completely.

OIL.

Oil flues need to be cleaned and inspected annually because deposits of soot may build up on the interior walls of the chimney. The amount of soot depends on how well tuned the boiler is and whether the house provides sufficient air for combustion. Excessive soot causes problems ranging from inefficient boiler operation to completely blocked chimneys.

To the extent that problems with either of these heating systems interfere with the flow of toxic gases and particles out of the house, they may also force carbon monoxide into the home. They may cause a one-time, high-level exposure situation or release smaller amounts more regularly over a longer period. These problems should never be ignored.

WHAT IS CARBON MONOXIDE?

WHY IS CARBON MONOXIDE POISONING ON THE RISE?

WHY IS CHIMNEY MAINTENANCE IMPORTANT?

PREVENTING PROBLEMS