The firebox is the area of your heating system where fuel combustion takes place. A firebox should be swept and inspected annually to ensure it is safe for operation and meets applicable fire codes.
The smoke chamber is found above the damper. An effective smoke chamber is shaped like an upside down funnel; it enables smoke and other products of combustion to transition into the flue. The smoke chamber is commonly constructed of masonry corbels. Fire code requires that the surface of the smoke chamber be parged smooth with a refractory insulating material. This application protects exposed brick cores and ensures that the smoke chamber wall thickness meets code specifications. Chimney Master can perform an inspection to determine if the smoke chamber in your heating system is safe for operation and up to code.