Finishing Requirements - Lennox Hearth Products Montebello LSM40MN-2 Installation Instructions Manual

If the air shutter opening is too small 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, appliance inside surfaces and on exterior
surfaces adjacent to the vent termination. Soot-
ing is caused by incomplete combustion in the
flames and lack of combustion air entering the
air shutter opening. To achieve a warm yellow
to orange flame with an orange body that does
not soot, the shutter opening must be adjusted
between these two extremes.
No smoke or soot should be present. Reposition
the logs if flames impinge on any of them.
If the logs are properly positioned and soot-
ing conditions exist, the air shutter opening
on the main burner tube should be adjusted.
Normally, the more offsets in the vent system,
the greater the need for the air shutter to be
opened further.
Burner Adjustment
WARNING
Air shutter adjustment should
only be performed by a qualified
professional service techni-
cian.
To adjust the flame, rotate the air shutter toward
the back or toward the front of the fireplace.
Position the air shutter to the factory setting as
shown in the table in Figure 38. Allow the burner
to operate for at least 15 minutes. Observe the
flame continuously. If it appears weak or sooty
as previously described, adjust the air shutter
until the flame appearance is as desired.
Use the extension knob (refer to Figure 34), to
adjust the flame height as desired, by sliding
the knob over the variable flame adjustment
knob located on the front of the valve. Replace
the extension knob back to the hanger after
the adjustment.
22
Propane models may exhibit a flame pattern
that may candle or appear stringy. If this is
problematic or persists as the appliance is
continually operated, adjust the air shutter
closed as described in the previous paragraphs.
Operate the appliance for a period of time as the
effect diminishes, ensuring that the appliance
does not develop sooty flames. When satisfied
that the appliance operates properly, proceed
to finish the installation.
Leave the control knob in the ON position and
the remote switch OFF.
Air Shutter
Opening
Venturi
Orifice
Valve
Burner
Venturi
Main Burner Factory Air Shutter
Opening Setting - Inches (millimeter)
Model Nat.Gas Propane Gas
LSM40-2 1/16 (1.59)
LSM45-2 1/16 (1.59)
Figure 38
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.

FINISHING REQUIREMENTS

Wall Details
Complete finished interior wall. To install the
appliance facing flush with the finished wall,
position framework to accommodate the thick-
ness of the finished wall (Figure 39).
Combustible
Finished Wall
Materials
Header
(2x4's)
Combustible
materials are
allowed above
this point on
the face of the
appliance.
8-3/8" Min.
(213 mm)
The gray shaded
area must be
Gas
non-combustible
or Dura Rock
1
Installations with horizontal terminations which have minimum
vertical vent height only will require 4"(102mm) minimum
side clearance as shown in shaded zone above. All other
installations require 1" (25mm) minimum side clearance as
specified in Table 4 on Page 5.
9/2 (7.14)
* Insulation is NOT ALLOWED in the clearance zones around vent
9/2 (7.14)
components. Keep this area free from combustible materials.
Figure 39
3" Min.
(76 mm)*
2 Foot Vertical
Vent & 90° Elbow
1
*
Top of
Appliance
Spacers
Top of Door Frame
Fireplace (right side)