A residential home was destroyed by fire that had originated in the attic in the vicinity of a propane furnace vent.
An ACS engineer investigated the fire. After ruling out electrical systems in the area of origin, it was determined that the propane furnace had been venting into the attic space rather than externally from the structure. This did not comply with the National Fuel Gas Code (NFPA 54). Over time, pyrolysis of the wooden components to the roof frame caused ignition.
