Page 16 18954-0-0705
Figures 16 and 19 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 17 and 20 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.
VFSR PILOT
Correct appearance of pilot flame.
Figure 16
Incorrect appearance of pilot flame.
Figure 17
If pilot flame pattern is incorrect, as shown in Figure 17
• See Troubleshooting, page 19.
Cleaning and Maintenance/Pilot
Oxygen Depletion Sensor Pilot (Figure 18 )
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.
Figure 18
VFSV AND VFSM PILOT
Correct Pilot Flame Pattern
Figure 19
Incorrect Pilot Flame Pattern
Figure 20
If pilot flame pattern is incorrect, as shown in Figure 20
• See Troubleshooting, page 19.
PILOT FLAME CHARACTERISTICS