Installation
900738-00 04/2017
Innovative Hearth Products
MHD35 Series Direct-Vent Gas Fireplaces
41
15.
Traditional Fireplaces: Install the Logs, Volcanic Stone, and Glowing Embers
1.
See
Page 54
for instructions on
Installing the logs, volcanic stone, and glowing embers
.
16.
Install the Glass Door
1.
See
Page 56
for instructions on
Installing and removing the glass door
.
17.
Adjust the Air Shutter to Ensure Proper Flame Appearance
WARNING
• Air shutter adjustment should only be performed by a qualifi ed professional service technician.
• Ensure glass door is in place and sealed during adjustment.
CAUTION
• 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 fl ame appearance.
Flame Appearance and Sooting
The fl ame should be blue at the base, and yellow-orange in the body of the fl ame.
When the fi replace is fi rst lit, the entire fl ame may be blue and will gradually turn yellow-orange during the fi rst 15
minutes of operation. If the fl ame remains blue, or if the fl ame 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 fl ames. Sooting results in black deposits forming on the logs, fi replace inside surfaces, and
on exterior surfaces adjacent to the vent termination.
Sooting is caused by incomplete combustion in the fl ames and lack of combustion air entering the air shutter
opening. To achieve a warm yellow-orange fl ame 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, fi rst check the log set positioning to ensure that the fl ames 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 fi replace operated with the air shutter opened too far may have fl ames that appear blue and transparent.
These weak, blue, and transparent fl ames are termed anemic.
•
Propane models may exhibit fl ames that candle or appear stringy. If this condition is present and persists, adjust
the air shutter to a more closed position, then operate the fi replace for a few more minutes to ensure that the
fl ame normalizes and the fl ames 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
Figure 39 - Air Shutter Adjustment Rod
Amount of Primary
Air
Flame Color
Air Shutter Adjustment
Air Shutter
Adjustment
Rod Down
(Fully-Open
Position)
Burner
Tube
Adjustment
Rod Up
(Fully-Closed
Position)
Adjustment
Set-Screw
If air shutter is
closed too far
Flame will
be orange
Air shutter gap should be increased
If air shutter is
open too far
Flame will
be blue
Air shutter gap should be decreased
1.
Move the adjustment rod down to increase air fl ow and up to decrease it. The rod is located in the lower control
compartment. Position the air shutter to the factory setting
(
Table 29
)
.