A manual "high-low" switch should be switched to "high" or "auto":

A manual "high-low" switch should be switched to "high" or "auto":



a. As soon as the main flame has stabilized
b. Prior to ignition of the main flame
c. When pressure is too low
d. When the boiler has been properly warmed up
e. During boiler pre-purge








Answer: D


Learn More :

Power Engineering

Learn More Multiple Choice Question :