Pilot Flame Characteristics; Main Burner Flame Characteristics - Empire DV-25-5SG Manual De Uso

The correct flame will be almost horizontal, blue and will extend past
the thermopile 1/4" (6mm). The flame will surround the thermopile
just below the tip.
On propane (LP-gas) slight yellow might occur where the pilot flame
and burner flame meet.
Natural gas pilots require adjusting when the inlet pressure is above
5" w.c. (1.25kPa) Turn adjustment screw clockwise to reduce flame.
Propane (LP-gas) will not require adjusting.

Main Burner FlaMe cHaracteristics

There will be a short blue inner flame with a much larger lighter blue
secondary flame. The burner flame may have a yellow tip when
hot. See the burner drawing showing the approximate heights of
each part of the flame. Dust in the combustion air will produce an
orange or red flame. Do not mistake the orange or red flame for
an improper yellow flame. After use, cleaning may be required for
the proper flame.
Primary air adjustment (Figure 11)
An air adjustment bolt is located on the chamber support bottom.
The four inch (102mm) clearance between the furnace and the floor
allows access to the air adjustment bolt. The air adjustment bolt is
above the rectangular opening on the inner casing bottom.
37408-0-0616

Pilot FlaMe cHaracteristics

Figure 10
On Propane gas, if a whistling noise (resonation) occurs, screw
air adjustment bolt into the chamber support in order to reduce
the amount of primary air. If the whistling noise (resonation) is not
eliminated when the air adjustment bolt is screwed into the chamber
support this may indicate the air adjustment bolt is misaligned. Grasp
air adjustment bolt and pivot (push) air adjustment bolt away from
yourself. Observe the main burner flame as you push air adjustment
bolt and when the main burner flame begins to develop a yellow
flame, you should stop pushing on the air adjustment bolt. Screw
air adjustment bolt out of the chamber support until the yellow flame
on the main burner is eliminated. The air adjustment bolt should
now be properly aligned. The reduction in primary air will soften the
main burner flame and will eliminate the whistling noise (resonation).
On Propane or Natural gas, if a yellow flame occurs, screw air
adjustment bolt out of the chamber support but do not completely
remove air adjustment bolt from chamber support. The repositioning
of the air adjustment bolt will increase the amount of primary air.
The increase in primary air will sharpen the main burner flame and
will eliminate the yellow flame.
Figure 9
Figure 11
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