CleaverBrooks FLX Operation, Service And Parts Manual page 24

Chapter 2
FIRING MODES
Different modulation modes are available with the Profire V burner. The Model FLX will utilize one of the
following:
Low - High -Low (60% damper purge).
Low - High -Low (open damper purge).
Full Modulation (open damper purge).
See following pages for operating descriptions of each firing mode
2-12
Profire V Burner
.
750-177