___ systems are commonly used to cool large buildings such as hotels and stadiums.

If a flame scanner does not prove a pilot flame during the pilot flame-establishing period, the pilot ___ will be de-energized, preventing fuel flow to the burner.

A faulty safety valve could cause a boiler explosion.

Run period is the period after ignition trials but before the operating set point is reached while the main burner is firing.

Steam allowed to enter the Bourdon tube of a pressure gauge can result in a false reading and/or cause damage from warping.

Hot water heating systems transfer heat by circulating heated water to and from a building space.

During a boiler inspection, the main steam stop valve is ___.

During a boiler inspection, the main steam stop valve is ___.

Steam allowed to enter the Bourdon tube of a pressure gauge can result in a false reading and/or cause damage from warping.

When water and sulfur combine, they react to form ___, which corrodes boiler metal.