Can I use my chimney with my new furnace?

Because furnace technology has significant advanced in the past few years, older chimneys may not be compatible with new furnaces for several reasons including size, dimensions, ventilation efficiency and construction materials. Modern furnaces are more efficient than conventional furnaces, transferring more heat into your home and less heat up the chimney than older units. Although this is much more energy-efficient, it also means that preexisting chimneys may be too big for the new furnace. If the chimney is too large, it could result in improper ventilation of flue products and development of condensation within the chimney. Inadequate ventilation may also violate building codes. Older chimneys may also not be in the right location or of the right height for newer furnaces. Additionally, the general condition and lining of the chimney may not meet the needs of a new furnace installation.