8
35048 Rev L
03/04
IB75 B-VENT GAS APPLIANCE
4.Chase/Termination Installation
Figure 8 and Table 1 specify minimum vent heights for
various pitched roofs.
These vent heights are necessary for safety and do
not ensure draft-free operation. Trees, buildings,
adjoining roof lines, adverse conditions, etc. may create
a need for a taller vent should down drafting occur.
Figure 8
Vent Height for Vertical Termination
Roof Pitch
H (Min.) Ft.
Flat to 6/12 ................................................ 1.0
6/12 to 7/12 ............................................... 1.25
Over 7/12 to 8/12 ...................................... 1.5
Over 8/12 to 9/12 ...................................... 2.0
Over 9/12 to 10/12 .................................... 2.5
Over 10/12 to 11/12 .................................. 3.25
Over 11/12 to 12/12 .................................. 4.0
Over 12/12 to 14/12 .................................. 5.0
Over 14/12 to 16/12 .................................. 6.0
Over 16/12 to 18/12 .................................. 7.0
Over 18/12 to 20/12 .................................. 7.5
Over 20/12 to 21/12 .................................. 8.0
Table 1 - Vent Height
Note:
To ensure proper operation, verify all venting
and the termination are unobstructed.
6.Check the Vent System
Test the venting system periodically to assure proper
operation. This can be done with a match while the
appliance is operating.
Hold a lighted match at the top edge of the appliance
opening. If the flames and smoke remain upright,
ventilation is acceptable. If the flames and smoke are
drawn into the appliance, this means ventilation is
good. If the flames and smoke are forced away from
the appliance, this may indicate a ventilation blockage
or down draft resulting in gas spillage into your home.
If this occurs, turn off the appliance and do not burn it
until it has been inspected by a qualified service
person.
If you have installed optional doors, close the doors
and conduct the test following the same instructions
above. See Figure 9.
Figure 9 - Testing Ventilation
5.Automatic Damper
This appliance comes with a thermally activated
automatic damper device. When at room temperature,
the damper will have slight spring pressure keeping it
in a closed position. When placed in a heat source
(i.e. when the appliance is turned on), the damper will
open as the thermally activated spring heats. Check
that the damper blade moves freely and does not
scrape or bind on any of the damper components.
While the appliance is in operation, visually check that
the damper opens. It will take approximately four
minutes for the spring to reach normal operating
temperature and the damper to reach a fully open
position.