Pilot Flame Characteristics - Empire Comfort Systems VFD26FM20N-2 Installation Instructions And Owner's Manual

Figures 15 and 18 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 16 and 19 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.
MILLIVOLT pILOT
Correct pilot Flame pattern
Incorrect pilot Flame pattern
If pilot flame pattern is incorrect, as shown in Figure 15
• See Troubleshooting, page 25.
Cleaning and Maintenance/pilot
Oxygen Depletion Sensor pilot
When the pilot has a large yellow tip flame, clean the Oxygen
Depletion Sensor as follows:
1. Clean the ODS pilot by loosening nut B from the pilot tubing.
When this procedure is required, grasp nut A with an open end
wrench.
2. Blow air pressure through the holes indicated by the arrows.
This will blow out foreign materials such as dust, lint and spider
webs. Tighten nut B also by grasping nut A.
Page 20

PILOT FLAME CHARACTERISTICS

Figure 15
Figure 16
Never use needles, wires, or similar cylindrical objects to
clean the pilot to avoid damaging the calibrated ruby that
controls the gas flow.
HYDRAULIC THERMOSTAT pILOT
Correct pilot Flame pattern
Incorrect pilot Flame pattern
If pilot flame pattern is incorrect, as shown in Figure 19
• See Troubleshooting, page 25.
WARNING
Figure 17
Figure 18
Figure 19
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