Crown Boiler CHC68-96 用户手册

10 

 
The chimney, vent, or any passageway for the stack gases to flow to the outdoor 
atmosphere is a very important part of the heating system. No furnace, regardless of the 
efficiency of the design, can perform satisfactorily when the chimney to which it is 
connected is inadequate or in poor condition. Any of the following symptoms may 
indicate a chimney has severe structural damage and is unsuitable for use. 
 

•  Chimney appears to be leaning to the side. 
•  Chimney appears to have structural damage, i.e. loose or missing blocks or 

bricks, or excessive deterioration at mortar joints. 

•  Tile liner damaged or missing. 
•  Flue gas leakage along the length of the chimney between the chimney 

connector and discharge termination. 

•  Excessive corrosion at the cleanout port or at the chimney connector entrance 

into the chimney.  

•  Structural debris, i.e. mortar or tile liner flakes, in base of the flue way. 

 
A qualified person shall inspect the chimney to confirm it is correctly sized for the 
application, properly constructed, and in sound condition.  Refer to the Standard for the 
Installation of Oil-Burning Equipment, NFPA 31-2001, for details on proper chimney 
sizing and construction. If needed, the chimney should be cleaned before installing the 
furnace. Any accumulation of dirt or debris at the bottom of the flue should be removed. 
 

Flue / Chimney / Vent Connector 
 

c CAUTION:  

•  DO NOT install a manual damper in the chimney or vent connector. 

•  Motorized and thermally- activated type vent dampers are NOT 

 
It is desirable to install the shortest vent connector (also referred to as a flue or chimney 
connector) possible with the fewest number of fittings, i.e. transitions and elbows. 
Generally, 6-inch diameter, 24 Ga. or heavier, single wall, lock seam-type, galvanized 
steel vent pipe and fittings are satisfactory materials for the fabrication of a vent 
connector. However, always consult local codes and authorities for specific minimum 
requirements. 
 
For some installations, it may be prudent to turn the furnace flue elbow 90 degrees 
clockwise, with respect to the front of the furnace, such that the elbow is open to the 
right-hand side of the unit, rather than upward. Turning the flue elbow may better 
facilitate connection of the vent connector piping to the flue elbow on the highboy and 
front flue, lowboy furnaces. Due to the presence of the fan and limit control and the 
wiring harness, the elbow may not be rotated 90 degrees counterclockwise. The 
installer must carefully mark and cut a hole in the furnace housing to allow the vent 
connector to pass through the housing.