Lennox Hearth MLDVTCD-35NE - Manual (Page 15)

15
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 8 - Burner Air Shutter Adjustment
Ref. Air shutter Patent:
U.S. Pat. 5,553,603
Air Shutter
Burner Tube
Adjustment Set-Screw
Main Burner Factory Air Shutter
Opening Setting - Inches (millimeter)
Model Natural Gas Propane Gas
MLDVTCD-35 (Closed)
Expose Half
Of The Hole
Adjustment Rod Up
(closed min. position)
Electronic Appliance Checkout
To light the burner, refer to the lighting instruc-
tions on Page 22. Ensure the igniter lights the
pilot. The pilot flame should engulf the flame
sensor as shown in Figure 10.
Figure 10
ELECTRONIC PILOT ASSEMBLY
Thermocouple
Thermopile
Pilot
Nozzels
SIT MILLIVOLT PILOT ASSEMBLY
3/8" Min.
(9 mm)
Igniter Rod Hood
Proper Pilot Flame Appearance
Millivolt Appliance Checkout
The pilot flame should be steady, not lifting
or floating. Flame should be blue in color with
traces of orange at the outer edge.
The top 3/8" (10 mm) at the pilot generator
(thermopile) and the top 1/8" minimum (tip)
of the quick drop out thermocouple should be
engulfed in the pilot flame. The flame should
project 1" (25 mm) beyond the hood at all three
ports. See Figure 9.
To light the burner, refer to the lighting instruc-
tions on Page 20.
Figure 9
Note: If the igniter is damaged, a
replacement kit is available, order
Catalog Number 87L54.
ELECTRONIC
Pilot
Hood
Sensor
Igniter
WARNINGS
• Air shutter adjustment should
only be performed by a quali-
fied professional service tech-
nician.
• Ensure front glass panel are
in place and sealed during
adjustment.
CAUTIONS
• Soot will be produced if the
air shutter is closed too much.
Any damage due to carboning
resulting from improperly
setting the air shutter is not
covered under the warranty.
• The air shutter door and nearby
appliance surfaces are hot.
Exercise caution to avoid
injury while adjusting flame
appearance.
• Ensure the air shutter setting is
at least equivalent to 1/2 of the
air hole exposed when operat-
ing the unit with propane gas.
Burner Air Shutter Adjustment Procedure
1. Locate and adjust the air shutter to the
standard setting, as shown in Figure 8.
2. Light appliance (follow lighting procedure on
lighting label in control compartment or see
the lighting instructions, Pages 20 and 22
in this manual).
3. Allow the burner to operate for at least 15 min-
utes while observing the flame continuously to
ensure that the proper flame appearance has
been achieved (see Figure 7 on Page 14). If
the following conditions are present, adjust
accordingly.
• If flame appears weak or sooty, adjust
the air shutter, incrementally, to a more
open position until the proper flame
appearance is achieved.
• If flame stays lowered blue, adjust the
air shutter, incrementally, to a more
closed position until the proper flame
appearance is achieved.
4. Leave the control knob (off/pilot/on) in the
ON position and the burner OFF/ON switch
OFF (and remote switches, if applicable).
5. When satisfied that the burner flame ap-
pearance is normal, close the lower control
compartment door.