Page 15
16717-2-0605
PILOT FLAME CHARACTERISTICS
Figures 13 and 16 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 14 and 17 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.
VFHS-20R PILOT
Correct appearance of pilot flame.
Figure 13
Incorrect appearance of pilot flame.
Figure 14
If pilot flame pattern is incorrect, as shown in Figure 14
• See Troubleshooting, page 19.
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.
Figure 15
VFHS-20/10T PILOT
Correct Pilot Flame Pattern
Figure 16
Incorrect Pilot Flame Pattern
Figure 17
If pilot flame pattern is incorrect, as shown in Figure 17
• See Troubleshooting, page 19.
