Lennox Hearth 875027M - Manual (Page 13)

13
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
Figure 14 - Burner Flame Appearance
(Rustic Oak Logs Shown) LSM45-2
Figure 13 - Burner Flame Appearance
(Birch Logs Shown) LSM40-2
LENNOX HEARTH PRODUCTS • MONTEBELLO ® DV GAS FIREPLACES (LSM40/45MN-2, LSM40/45MP-2, LSM40/45EN-2) • CARE AND OPERATION INSTRUCTIONS
BURNER ADjUSTMENTS
(QUALIFIED TECHNICIANS ONLY)
Flame Appearance and Sooting
Proper flame appearance is a flame which is
blue at the base and becomes yellowish-orange
in the body of the flame. When the appliance
is first lit, the entire flame may be blue and will
gradually turn yellowish-orange during the first
15 minutes of operation. After 15 minutes of
operation, if the flame is 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, appliance inside
surfaces and on exterior surfaces adjacent to
the vent termination.
Sooting is caused by incomplete combus-
tion in the flames and lack of combustion air
entering the air shutter opening. To achieve a
warm yellowish-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 there is smoke or soot 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 still exists, then the air
shutter opening should be increased.
• The more offsets in the vent system, the larger
the air shutter opening will need to be.
• An appliance 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 which
candle or appear stringy. If this is present
and persists, adjust the air shutter to a more
closed position, then operate the appliance
for a few more minutes to ensure that the
flame normalizes and the flames do not
appear sooty.
The following chart is provided to aid you in
achieving the correct air shutter adjustment for
your installation.
Air Shutter Adjustment Guidelines :
Amount of
Primary Air
Flame
Color
Air Shutter
Adjustment
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