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Figures 19 and 20 show a correct pilot flame pattern. The correct
flame will be blue and will extend beyond the thermocouple. The
flame will surround the thermocouple just below the tip. A slight
yellow flame may occur where the pilot flame and main burner
flame meet. Figures 21 and 22 show an incorrect pilot flame pattern.
The incorrect pilot flame is not touching the thermocouple. This will
cause the thermocouple to cool. When the thermocouple cools, the
heater will shut down.
Correct Pilot Flame Pattern for VFDR
Figure 19
Correct Pilot Flame Pattern for VFDT & VFDM
Figure 20
Incorrect Pilot Flame Pattern for VFDR
Figure 21
Incorrect Flame Pattern for VFDT & VFDM
Figure 22
If pilot flame pattern is incorrect, as shown in Figures 21 and 22
• See Troubleshooting, page 31.
PILOT FLAME CHARACTERISTICS