Figure 20 - Natural Gas Flame Appearance; Figure 21 - Propane Gas Flame Appearance - Evcon DGAM056BDD Installation Instructions Manual

However, the amount of combustion air required will vary
depending on altitude, actual BTU. content of the gas be-
ing used, gas pressure, conversion to another gas, and
other variable factors.
Therefore, it is essential that the burner flame be observed
and any necessary adjustments are made before the fur-
nace is put into service at the final home site. Adjusting the
burner air is considered part of the normal home set ---up
procedure and is the responsibility of either the home seller
or buyer, depending on their agreement. Adjustments of
this type are not covered by the warranty.
CAUTION
Combustion air adjustments must be made only by
a qualified technician. Improper air adjustment
may cause unsafe operation, explosion or asphyxi-
ation.
Correct Amount of
Primary Air
Correct Amount of
Primary Air
View of Burner Through the Observation Window
Too Little Primary Air
Push Shutter Rod In
Figure 20 -- Natural Gas Flame Appearance
Too Little Primary Air
Push Shutter Rod In
Figure 21 -- Propane Gas Flame Appearance
To adjust the combustion air:
1. To light and operate furnace see label inside lower fur-
nace door.
2. Allow the burner to burn for about 1 MINUTE.
3. Look through the observation window and observe the
appearance of the flame.
4. On natural gas, the base of the flame should be blue
but the tips of the flame will be yellow. (See Figure 20.)
5. On Propane gas, almost all of the flame will be yellow
although some blue should still be present at the base
of the flame next to the end of the burner. (See Figure
21.)
6. If the flame is too yellow, the combustion air should be
increased. If the flame is excessively blue (no yellow)
the combustion air should be decreased.
7. To adjust the combustion air, loosen the lock screw
holding the combustion air rod in place. Push in on the
rod to increase the combustion air. Pull out on the com-
bustion air rod to decrease the combustion air. Tighten
lock screw after adjustment is made. Do not complete-
ly close air damper at any time. Complete closure of air
damper to burner will result in improper operation. See
caution above.
24
Too Much Primary Air
Pull Shutter Rod Out
Too Much Primary Air
Pull Shutter Rod Out