Lennox Hearth MLDVTCD-35NE - Manual (Page 14)

14
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
LENNOX HEARTH PRODUCTS • MERIT ® SERIES DIRECT-VENT CONTEMPORARY DESIGN GAS FIREPLACES • MODEL MLDVTCD-35 • CARE AND OPERATION
Figure 7 - Burner Flame Appearance Model MLDVTCD-35
(River Stone And Beach Sand With Porcelain Panels Shown)
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
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 openings 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 appliance inside sur-
faces and on exterior surfaces adjacent to the
vent termination.
Sooting is caused by incomplete combustion
in the flames and lack of combustion air enter-
ing 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, 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.