www.fmiproducts.com
125009-01A
24
INSPECTING bURNERS
Check pilot flame pattern and burner flame
patterns often.
PILOT FLAME PATTERN
Figure 31 shows a correct pilot flame pattern.
Figure 32 shows an incorrect pilot flame pat
-
tern. The incorrect pilot flame is not touching
the thermocouple. This will cause the thermo-
couple to cool. When the thermocouple cools,
the heater will shut down.
If pilot flame pattern is incorrect, as shown
in Figure 32
• turn heater off (see
To Turn Off Gas to Appli-
ance
, page 21 [Thermostatically-Controlled
Models] or page 23 [Remote-Ready Mod
-
els])
• see
Troubleshooting
, page 28
Note: The pilot flame on natural gas units will
have a slight curve, but flame should be blue
and have no yellow or orange color.
Figure 31 - Correct Pilot Flame Pattern
(Your pilot may vary from pilots shown)
Pilot Burner
Thermocouple
Thermocouple
Figure 32 - Incorrect Pilot Flame Pattern
(Your pilot may vary from pilots shown)
Thermocouple
Thermocouple
Pilot Burner
FRONT bURNER FLAME PATTERN
Figure 33 shows correct front burner flame
pattern. Figure 34 shows incorrect front
burner flame pattern. The incorrect burner
flame pattern shows yellow tipping at top of
blue flame.
WARNING: If yellow tipping
occurs, your heater could pro
-
duce increased levels of carbon
monoxide. If front burner flame
pattern shows yellow tipping,
follow instructions at bottom of
this page. Yellow flame on rear
burner is normal.
NOTICE: Do not mistake orange
flames with yellow tipping. Dirt
or other fine particles are burned
by heater, causing brief patches
of orange flame.
Figure 33 - Correct Front Burner Flame
Pattern - VUL36 Shown
If front burner flame pattern is incorrect, as
shown in Figure 34
• turn heater off (see
To Turn Off Gas to Appli-
ance
, page 21 [Thermostat-Controlled Mod
-
els] or page 23 [Remote-Ready Models])
• see
Troubleshooting
, page 28
Figure 34 - Incorrect Front Burner Flame
Pattern - VUL36 Shown
Yellow Tipping
At Top of Blue
Flame
Propane/LP Gas Pilot
Natural Gas Pilot
Propane/LP Gas Pilot
Natural Gas Pilot