Flue Restrictors - Lennox Hearth Products Vintage VIN Installation And Operation Manual

Flue Restrictors

The flue restrictor settings shown in Figures 26 and 27 are for typical
installations and may need to be adjusted from standard to take into
account other variables in the installation to achieve proper combustion.
See Flue Restrictor Guidelines on this page to assist you in making a
proper flue restrictor adjustment.
The Vintage™ gas stove uses balanced flue technology to ensure proper
combustion. A flue restrictor may need to be installed depending on the
vent configuration of your stove. The drawings on Page 14 show all the
allowable pipe configurations for the Vintage gas stove. To properly install
the flue restrictor, find your pipe configuration in the drawings on Page
14 and note which restrictor setting is recommended. The flue restric-
tor and two black self-tapping 5/32" allen head screws can be found in
the firebox in a plastic bag. The restrictor should be placed over the flue
opening on the ceiling of the firebox. On the restrictor, two self-tapping
5/32" allen head screws should be installed in either holes 1, 2, 3, or 4
in the restrictor and screwed into the two holes in the firebox ceiling.
See the drawing to the right for the location of hole numbers on the
restrictor. The numbered holes in which the screws are inserted in the
restrictor should correspond to the restrictor position numbers found
on the drawings for your pipe configuration. Restrictor positions are
based on tests run in a laboratory. The optimum restrictor positions may
need to be adjusted slightly depending on the conditions surrounding
the residential installation. Do not adjust restrictors to a point where the
fireplace is sooting.
Notes: The higher the number of the flue restrictor position, the greater
amount of combustion air will be delivered.
Flue Restrictor Adjustment Guidelines
After the flue restrictors have been set to the standard settings as shown
in Figures 26 and 27, the burner flame appearance should be evaluated
to determined if the flue restrictors need to be set to a different position
to adjust for variables in your installation. Light the appliance and allow
it to burn for 20 minutes. See Flame Color and Behavior on Page 18 to
determine if you have a proper burner flame appearance. If the proper
flame appearance cannot be achieved, the flue restrictor may need to be
set to a different position. See the following guidelines to determine if
you need to readjust the flue restrictors.
Before proceeding, confirm the manifold and inlet gas pressure is correct,
primary air shutter is properly adjusted, venting system connections are
secure and not blocked and if you are at a high elevation, ensure unit has
been properly derated:
Symptoms - Lack of Combustion Air
If the symptoms listed below are present, you may need to adjust the
flue restrictor to a more open position.
• Flame appears yellow
• Floating Flames (lazy, ill defined, quiet, may roll)
• Sooting
• Pilot becomes yellow and appliance shuts down
Symptoms - Excessive Combustion Air
If the symptoms listed below are present, you may need to adjust the
flue restrictor to a more closed position.
• Low Flame
• Pilot pulls and appliance shuts down
• Pilot flame ghosts
Figure 23
Figure 24
Figure 25
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
4 3  1
Restrictor
Flue Opening in the
top of the firebox
A
Restrictor
Installed Over
A
Flue Opening
13