Burner Adjustments; Millivolt Appliance Checkout; Electronic Appliance Checkout - Lennox Hearth Products MPB-33 Homeowner's Care And Operation Instructions Manual

Burner Adjustments

Note - The air shutter for the burner primary
air opening is factory-set. Do not adjust the
factory-set position. The factory-set position
is shown in Figure 7.
Burner Air Shutter Adjustment
Ref. Air shutter Patent:
U.S. Pat. 5,553,603
Main Burner Factory Air Shutter
Opening Setting - Inches (millimeter)
Model Natural
Gas
MPB-3328 Fully Closed
MPB-3530 Fully Closed
MPB-4035 Fully Closed
MPB-4540 Fully Closed
Figure 7
SIT Millivolt Appliance Checkout
The pilot fl ame should be steady, not lifting
or fl oating. 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" min (tip) of the
quick drop out thermocouple should be engulfed
in the pilot fl ame. The fl ame should project 1"
(25 mm) beyond the hood at all three ports
(Figure 8).
To light the burner, refer to the lighting instruc-
tions on Pages 20 & 21.
SIT MILLIVOLT PILOT ASSEMBLY
Proper Pilot Flame Appearance
Thermocouple
Pilot
Propane
Nozzels
Gas
Figure 8
3/16"
(4.76 mm)
3/16"
(4.76 mm)
3/16"
(4.76 mm)
3/16"
(4.76 mm)
NOTE: DIAGRAMS & ILLUSTRATIONS ARE NOT TO SCALE.
Igniter Rod
Hood
3/8" Min.
(9 mm)
Thermopile

Electronic Appliance Checkout

To light the burner, refer to the lighting instruc-
tions on Pages20 and 21. Ensure the igniter
lights the pilot. The pilot fl ame should engulf
the fl ame sensor as shown in Figure 9.
ELECTRONIC PILOT ASSEMBLY
Proper Pilot Flame Appearance
Proper Flame
Adjustment
Pilot
Nozzels
Figure 9
With proper care and maintenance, your appli-
ance will provide many years of enjoyment. If
you should experience any problem, fi rst refer
to the trouble shooting guide in this manual.
If problem persists, contact your Lennox
distributor.
3/8" to 1/2"
(9 -13 mm)
Ground
Electrode
Flame Rod
Hot Surface
Igniter
9