U.S. Boiler Company B series 2 User's Information Manual - page 7
7
Figure 11: 1 Inch Main Burner Flame
Figure 10: 0mm Main Burner Flame
5. Adjust thermostat to highest setting.
6. Check main burner flames. See Figure 10 or 11.
Flame should have clearly defined inner cones with
no yellow tipping. Orange-yellow streaks caused
by dust should not be confused with true yellow
tipping. If yellow flames are observed, follow
instructions TO TURN OFF GAS TO APPLIANCE
(see Figure 4 or 5) and contact a qualified service
agency.
7. Adjust thermostat to normal setting.
D.
ScheduleInspectionbyQualifiedServiceAgency
(AnnualoratBeginningofHeatingSeason). For
continued safe operation a qualified service agency
must provide a more detailed inspection of burners, heat
exchanger and vent system, and provide maintenance
as specified in Installation, Operating and Service
Instructions.