My gas furnace is no longer heating properly. What is the most likely problem?
Most of our “replacement” gas furnaces are sold because the old furnace developed a crack in the heat exchanger. The crack is seldom visible to the untrained eye. Sometimes it is not visible to the most experienced technician but he is able to make a judgment call based upon the operation of the system. Maybe the pilot light keeps going out. Maybe a safety switch sometimes cuts the furnace off. Then the homeowner resets the furnace and it seems to work for a few days. Both of the above could be due to a cracked heat exchanger. As the “crack” gets larger, the chance that the furnace will malfunction becomes much greater. If the homeowner fails to see the symptoms, eventually a technician will be called for repairs.
