15
INSPECT CHIMNEY to make certain it is
constructed according to latest revision of the NFPA
211. Local codes may differ from this code and
should be checked. Where there is a conflict, local
code will prevail. In Canada refer to National Building
Code or CSA-A405 as applicable.
Boiler must be installed into chimney which has
masonry or metallic chimney liner.
Unlined chimney will have leaks that will cause poor
chimney performance (NO DRAFT), and could result
in poor positive pressure in combustion chamber.
Horizontal portions of venting system should
not exceed 10 feet in length. Horizontal lengths
over 10 feet will have negative effect on chimney
performance.
Chimney should extend at least 2 feet above any
portion of building within 10 feet. See figure #14.
It should produce negative draft of .06 to .08 inches
of water column, (W.C.), as measured with draft
gauge between boiler and barometric draft control
while maintaining .02 inch W.C. negative draft in
combustion chamber. See chart “Chimney or Vent
Sizes” 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
chimney approximately ¼” per foot. Bolt or screw
joints together to avoid sag.
If oil fired water heater is vented into same flue as
boiler, provide separate hole into chimney whenever
possible. When not possible, use “Y” connection in
flue pipe, using separate draft regulator for each
unit. When chimney will not provide adequate
draft to handle input from water heater and boiler
simultaneously, wire units so that only one will
operate at a time, favoring water heater.
CHImNey oR VeNt SIZeS
moDel No.
RoUND
INCHeS
SQUaRe
INCHeS
HeIGHt
feet
mIN maX mIN maX mIN maX
365,3100
4100
6
8
8X8
8X8
15
40
4125,3125
4150, 5125
7
8
8X8 8X10
15
40
5175,5200
8
10
8X8 8X12
15
50
6150,6225
8
10
8x8 8x12
15
50
7275
8
10
8x8 8x12
15
50
VENTING SYSTEM INSPECTION & INSTALLATION
Figure #14
