Install The Logs, Volcanic Stone, And Glowing Embers; Install The Glass Door And Replace The Barrier; Adjust The Air Shutter To Ensure Proper Flame Appearance - Superior Fireplaces MHD 35 Series Installation And Operation Instructions Manual

Innovative Hearth Products
MHD 35/40 Series Direct-Vent Gas Fireplaces
Traditional Fireplaces: Install the Logs, Volcanic Stone, and Glowing Embers
17.
1. See Page 54 for instructions on Installing the logs, volcanic stone, and glowing embers.
Install the Glass Door
18.
1. See Page 58 for instructions on Installing and removing the glass door.

Adjust the Air Shutter to Ensure Proper Flame Appearance

19.
• Air shutter adjustment should only be performed by a qualified professional service technician.
• Ensure glass door is in place and sealed during adjustment.
• Soot will be produced if the air shutter is closed too much. Any damage due to sooting,
resulting from improperly setting the air shutter, is not covered under the warranty.
• The air shutter rod and nearby appliance surfaces are hot. Exercise caution to avoid injury
while adjusting flame appearance.
Flame Appearance and Sooting
The flame should be blue at the base, and yellow-orange in the body of the flame.
When the fireplace is first lit, the entire flame may be blue and will gradually turn yellow-orange during the first 15
minutes of operation. If the flame remains blue, or if the flame is orange with evidence of sooting (black tip), the air
shutter opening may need to be adjusted.
If the air shutter opening is closed too far, sooting may develop. Sooting is indicated by black puffs developing at the
tips of very long orange flames. Sooting results in black deposits forming on the logs, fireplace inside surfaces, and
on exterior surfaces adjacent to the vent termination.
Sooting is caused by incomplete combustion in the flames and lack of combustion air entering the air shutter
opening. To achieve a warm yellow-orange flame with an orange body that does not soot, the shutter opening must
be adjusted between these two extremes.
Air Shutter Adjustment Guidelines
• If smoke or soot is present, first check the log set positioning to ensure that the flames are not impinging on any
of the logs. If the log set is properly positioned and a sooting condition persists, then the air shutter should be
opened more.
• The more offsets in the vent system, the wider the air shutter will need to be opened.
• An fireplace operated with the air shutter opened too far may have flames that appear blue and transparent.
These weak, blue, and transparent flames are termed anemic.
• Propane models may exhibit flames that candle or appear stringy. If this condition is present and persists, adjust
the air shutter to a more closed position, then operate the fireplace for a few more minutes to ensure that the
flame normalizes and the flames do not appear sooty. The following chart is provided to help achieve the correct
air shutter adjustment for your installation.
Table 28 - Air Shutter Adjustment Guidelines
Amount of Primary
If air shutter is
closed too far
If air shutter is
open too far
1. Move the adjustment rod down to increase air flow and up to decrease it. The rod is located in the lower control
compartment. Position the air shutter to the factory setting (Table 29).
Flame Color
Air
Flame will
Air shutter gap should be increased
be orange
Flame will
Air shutter gap should be decreased
be blue
WARNING
CAUTION
Figure 39 - Air Shutter Adjustment Rod
Air Shutter Adjustment
Adjustment
Set-Screw
Adjustment
Rod Up
Burner
(Fully-Closed
Tube
Position)
Air Shutter
Adjustment
Rod Down
(Fully-Open
Position)
Installation
900414-00 12/2015
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