The correct pilot flame (Figure 11) will be blue, extending past
the thermocouple. The flame will surround the thermocouple just
below the tip.
Natural gas pilots require adjusting when the inlet gas pressure is
above 5" w.c. Remove the pilot cover screw on the control valve
(Figure 3, page 8), and turn the adjustment screw clockwise to
reduce flame. Replace pilot cover screw to eliminate gas leaking
at that control valve opening.
LP gas (propane) will not require adjustment.
After use, cleaning may be required for the proper flame.
MAIN BURNER FLAME CHARACTERISTICS
The correct flame will be a short blue inner flame with a much
larger light blue outer flame. The main burner (Figure 12) shows
the approximate height of each part of the flame for each gas. The
burner does not have a primary air adjustment. The flame will be
correct if the factory-set pressure and orifice opening are used. After
the furnace has been operating, the burner ports may be blocked by
foreign matter carried in by combustion air. Therefore, cleaning of
the burner may be needed for proper flame.
To clean burner port disconnect the gas supply to the valve, and
remove the eight screws fastening the burner door. after remov-
ing the burner door from the combustion chamber, remove rear
burner, pilot burner and front burner. With front and rear burners
removed from furnace, force water into the ribbon ports and dry
with air pressure.
12431-12-1109
PILOT FLAME CHARACTERISTICS
PROPER FLAME ADJUSTMENT
Figure 11
Figure 12
Page 13