When switching from a solid fuel (oil, wood, coal, pellet, etc.) to natural gas, it is very important that your home's chimney and/or exhaust flue pipe be cleaned and inspected by a qualified service person. Although natural gas appliances do not produce visible soot that solid fuel burning appliances do, they do produce more moisture in their exhaust. This moisture combined with the residue (soot) that can remain in a flue may lead to deterioration of a masonry chimney. This deterioration can lead to poor venting conditions, improper draft, and unsafe operation of your heating system. Therefore, the National Fuel Gas Code indicates that all chimneys shall be properly lined prior to the installation of a natural gas appliance.
With respect to the new high efficiency heating systems, your masonry chimney or flue pipe may not be compatible. In fact, some of the high efficiency heating systems available today are directly vented through the exterior wall with the use of a plastic vent pipe or require the use of a stainless steel chimney liner if an existing masonry chimney is to be used. When purchasing high efficiency equipment, it is important for you to ask your heating contractor if your system will need special venting requirements.
Regardless of the heating fuel used in your home, it is highly recommended that you have an annual heating system tune-up, the equipment serviced, as well as an inspection of the chimney and/or flue, which are critical to the safe operation of the system. Maintaining these vital systems will ensure the safety and maximum efficiency of your heating system for years to come.