Design Dynamics PFS VF-18P-MHD - Manual (Page 19)

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Thermocouple
Thermocouple
Figure 22 - Incorrect Pilot Flame Pattern
(Natural Gas Pilot Shown)
Figure 21 - Correct Pilot Flame Pattern
(Natural Gas Pilot Shown)
BURNER FLAME PATTERN
Figure 23 shows correct burner flame pat-
tern.
NOTICE: Do not mistake orange
flames with yellow tipping. Dirt
or other fine particles are burned
by heater, causing brief patches
of orange flame.
If burner flame pattern is incorrect, as shown
in Figure 24
• turn appliance off (see To Turn Off Gas to
Appliance, page 18)
• see Troubleshooting, page 21
Figure 23 - Correct Burner Flame Pattern
Figure 24 - Incorrect Burner Flame
Pattern
Blue & Bright
Yellow Flames
Orange
Flames
INsPeCTING BURNeRs
Check pilot flame pattern and burner flame
patterns often.
PILOT FLAME PATTERN
Figure 21 shows a correct pilot flame pattern.
Figure 22 shows an incorrect pilot flame pat-
tern. The incorrect pilot flame is not touching
the thermocouple. When the thermocouple
cools, the heater will shut down.
If pilot flame pattern is incorrect, as shown
in Figure 22
• turn heater off (see To Turn Off Gas to Ap-
pliance, page 18)
• see Troubleshooting, page 21
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.