Lennox Hearth VIN operation manual Flue Restrictors, Flue Restrictor Adjustment Guidelines

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

14and 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

4 3 2 1

Restrictor

Figure 23

Flue Opening in the top of the firebox

A

Figure 24

Restrictor

Installed Over A

Flue Opening

Figure 25

NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

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