If an induced-draft gas burner produces a flame that is completely blue, or blue with tiny yellow tips, it is an
indicator of _____.
a. incomplete combustion
b. normal operation
c. too much primary air
d. too much secondary air
Question 2
In order for combustion to occur, there must be _____.
a. fuel, CO2, and ignition
b. radiation, conduction, and convection
c. fuel, oxygen, and aldehyde
d. fuel, heat, and oxygen