Smith Cast Iron Boilers GB300 - Manual (Page 5)

GB300 BOILER INSTALLATION AND OPERATION INSTRUCTIONS
Page 5
CHIMNEY & VENT PIPE CONNECTIONS
WARNING: The vent installation must be in
accordance with Part 7, Venting of Equipment, of
the National Fuel Gas Code, ANSI Z223.1/NFPA54-
latest revision or applicable provisions of the
local building codes. Canadian installa-tions
must comply with CAN /CGA B149.1 or .2
Installation Code. Improper venting of this boiler
can result in excessive levels of carbon
monoxide, which can result in severe personal
injury or death!
Chimney Inspection & Sizing
If this boiler will be connected to a masonry chimney, a
thorough inspection of the chimney must be performed.
Ensure that the chimney is clean, properly constructed
and properly sized. Table 2 lists the equivalent breeching
and flue sizes required for the GB300 boilers.
Table 2 Vent Outlet, Equivalent Breeching
& Chimney Size
When more than one appliance is connected to the same
chimney flue the flue must be large enough to safely
vent the combined output of all the appliances.
WARNING: If an appliance using any type of a
mechanical draft system operating under
positive pressure is connected to a chimney flue,
never connect any other appliances to this flue.
Doing so can result in the accumulation of
carbon monoxide which can cause severe
personal injury or death!
VENT CONNECTIONS
Always use a type B or single wall galvanized metal vent
pipe the same diameter as the draft hood flue collar. Use
the shortest, straightest vent system possible for the
installation. If horizontal runs exceed 6 feet they must
be supported at maximum 6 foot intervals with overhead
hangers. The vent system should be sloped up towards
the chimney at a minimum rate of 1/4 inch/foot and
terminate flush with the inside of the chimney flue.
Fasten each connection with at least 3 corrosion
resistant sheet metal screws.
WARNING: Never modify or alter any part of the
boiler’s draft hood. This includes the removal or
alteration of any baffles. Never install a vent pipe
of a diameter different than that of the boiler
draft hood flue collar. Failure to comply with this
warning can result in severe personal injury or
death.
Always provide a minimum clearance of 6 inches between
type C vent pipe and any combustible materials. Type
B1 vent may be used, clearance between it and any
combustible material must be as listed.
WARNING: Failure to maintain minimum
clearances between vent connectors and any
combustible material can result in a fire causing
extensive property damage, severe personal
injury or death!
Vent Outlets
Equivalent Breeching
& Chimney size
Boiler Diameter
Model
# of outlets/dia. in inches
inches mm
GB300-5 1@10 10 254
GB300-6 1@12 12 305
GB300-7 1@12 12 305
GB300-8 2@10 14 356
GB300-9 2@10 14 356
GB300-10 2@10 14 356
GB300-11 2@12 15 381
GB300-12 2@12 15 381
GB300-13 2@12 15 381
GB300-14 1@12, 2@10 16 406
GB300-15 4@10 17 432
GB300-16 4@10 17 432
GB300-17 4@10 17 432
GB300-18 4@10 17 432
GB300-19 4@10 17 432
NOTE: These sizes are based on a 20 foot chimney height.