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VENTING SY
VENTING SY
VENTING SY
VENTING SY
VENTING SYSTEM INSPECTION & INST
STEM INSPECTION & INST
STEM INSPECTION & INST
STEM INSPECTION & INST
STEM INSPECTION & INSTALLA
ALLA
ALLA
ALLA
ALLATION
TION
TION
TION
TION
WARNING:
WARNING:
WARNING:
WARNING:
WARNING:
BOILER IS TO BE VENTED BY NATURAL DRAFT AND SHALL
NOT BE CONNECTED INTO ANY PORTION OF A MECHANICAL DRAFT SYSTEM
OPERATING UNDER A POSITIVE PRESSURE.
INSPECT CHIMNEY to make certain it is constructed according to the latest revision of
the NFPA211. Local codes may differ from this code and should be checked. Where there
is a conflict, the local code will prevail. In Canada refer to the National Building Code or
CSA-A405 as applicable.
This boiler must be installed into a chimney which has a masonry or metallic chimney
liner.
An unlined chimney will have leaks that will cause poor chimney performance (NO
DRAFT), and could result in poor positive pressure in the combustion chamber.
Horizontal portions of the venting system should not exceed 10 feet in length. Horizontal
lengths over 10 feet will have a negative effect on the chimney performance.
The chimney should extend at least 2 feet above any portion of the building within 10
feet. See figure 14 below. It should produce a negative draft of .06 to .08 inches of water
column, (W.C.), as measured with a draft gauge between the boiler and barometric draft
control while maintaining an .02 inch W.C. negative draft in the combustion chamber. See
chart below for recommended chimney or vent sizes.
Inadequate draft will cause improper combustion, resulting in dirty flue ways and high fuel
bills.
CONNECT FLUE PIPE same size as boiler outlet to chimney, sloping upward
continuously toward the chimney approximately 1/4" per foot. Bolt or screw joints together
to avoid sag.
If an oil fired water heater is vented into the same flue as the boiler, provide a separate
hole into the chimney whenever possible. When this isn’t possible, use a “Y” connection in
the flue pipe, using a separate draft regulator for each unit. When a chimney will not provide
adequate draft to handle the input from the water heater and boiler simultaneously, wire the
units so that only one will operate at a time, favoring the water heater.
CHIMNEY OR VENT SIZES
ROUND
SQUARE
HEIGHT
MODEL NO.
INCHES
INCHES
FEET
MIN MAX MIN MAX MIN MAX
SFH365,3100
4100
6
8
8X8
8X8
15
40
SFH4125,3125
4150, 5125
7
8
8X8 8X10
15
40
SFH5175,5200
8
10
8X8 8X12
15
50
SFH6150,6225
8
10
8x8
8x12
15
50
SFH7275
8
10
8x8
8x12
15
50
FIGURE 14
