12
WARNING
Boiler and venting installations shall be performed
by a quali
fi
ed expert and in accordance with the
appropriate manual. Installing or venting boiler
or other gas appliance with improper methods or
materials may result in serious injury or death due
to
fi
re or to asphyxiation from poisonous gases such
as carbon monoxide with is odorless and invisible.
!
WARNING
Do not connect boiler to any portion of mechanical
draft system operating under positive pressure.
!
• Inspect chimney. Verify construction in accordance
with requirements of provincial building codes or, in
the absence of such regulations, in accordance with
National Building Code of Canada, or CAN/CSA - A405.
Local regulations may differ from this code and should
be checked. Where there is a con
fl
ict, the local code will
prevail.
• Install boiler 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
positive pressure in the combustion chamber.
• Horizontal portions of venting system should not exceed
10 ft. in length. Horizontal lengths over 10 ft. will have
negative effect on chimney performance.
• Chimney should extend at least 2 ft. above any portion
of building within 10 ft.
See Figure 15 .
It should produce
a -.06 to -.08 inch W.C. draft, as measured with draft
gauge between boiler and barometric draft control while
maintaining .02 inch W.C. negative draft in combustion
chamber. See "Chimney or Vent Sizes" chart for
recommended minimum and maximum chimney or vent
sizes.
• Inadequate draft will cause improper combustion,
resulting in dirty
fl
ue ways and high fuel bills.
• Connect
fl
ue pipe same size as boiler outlet to chimney,
sloping upward continuously toward the chimney
approximately ¼" per foot. Bolt or screw joints together
to avoid sag.
• If oil
fi
red water heater is vented into same
fl
ue as boiler,
provide separate hole into chimney whenever possible.
When this isn’t possible, use “Y” connection in
fl
ue
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 only one will operate at a time, favoring water heater.
Table 6 CHIMNEY OR VENT SIZES
MODEL NUMBER
ROUND
INCHES
SQUARE
INCHES
HEIGHT (FT)
MIN MAX MIN MAX MIN MAX
OBC3O
6
8
8x8
8x10
15
40
BC4
6
8
8x8
8x10
15
40
VENTING SYSTEM INSPECTION & INSTALLATION
Figure 15
Chimney Installation
• Install Vent Safety Switch follow instructions included
with kit. See
Figure 16
.
