User Manual

32
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
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.
Main Burner Factory Air Shutter
Opening Setting - Inches (millimeter)
Model Nat.Gas Propane Gas
MLDVT-30 1/32 (0.794) 1/8 (3.175)
MLDVT-35 1/32 (0.794) 1/8" (3.2)
MLDVT-40 1/32 (0.794) 1/4" (6.4)
MLDVT-45 1/32 (0.794) 3/16" (4.8)
Air Shutter
Adjustment Rod
Down (fully open
air opening posi-
tion)
Burner
Tube
Adjustment Set-Screw
Figure 50 - Burner Air Shutter Adjustment
Ref. Air shutter Patent:
U.S. Pat. 5,553,603
Figure 51 - Burner Flame Appearance Model MLDVT-30 & MLDVT-35
Figure 52 - Burner Flame Appearance Model MLDVT-40 & MLDVT-45
Adjustment Rod Up
(closed min. position)
LENNOX HEARTH PRODUCTS • MERIT
®
SERIES DIRECT-VENT GAS FIREPLACES • MODELS MLDVT-30/35/40/45 • INSTALLATION INSTRUCTIONS
1. Locate adjustment rod and adjust air shutter
to the standard setting as shown in Figure
50 (adjustment rod is located in the lower
control compartment).
Note: Move the adjustment rod down to
decrease air and up to increase.
2. Light appliance (follow lighting procedure
on lighting label in control compartment or
see the Care and Operation Manual).
3. Allow the burner to operate for at least 15
minutes while observing the flame continu-
ously to ensure that the proper flame ap-
pearance has been achieved (see Figures
51 and 52). If the following conditions are
present, adjust accordingly.
• If ame appears weak or sooty, adjust
the air shutter, incrementally, to a more
open position until the proper flame
appearance is achieved.
• If ame 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 satised that the burner ame appear-
ance is normal, re-install the lower control
compartment door then proceed to finish
the installation.
Burner Air Shutter Adjustment Procedure