Minnesota Boiler License Practice Exam 2026 – All-in-One Guide to Passing with Confidence

A device that controls the stopping and starting of the burner on a hot water boiler is known as an aqua-stat. This component is essential for maintaining the water temperature within the boiler at a designated set point. When the water temperature falls below the set point, the aqua-stat activates the burner to heat the water. Conversely, once the temperature reaches or exceeds the set point, the aqua-stat shuts off the burner to prevent overheating. This regulation helps ensure efficiency and safety within the hot water system.

Other options, like the pressure trol, monitor and control pressure levels within the boiler system but do not specifically manage burner operation based on temperature. Low water cut outs are safety devices that shut off the burner when the water level drops below a certain point, preventing damage to the boiler. Sail switches are used for air-flow mechanisms and are not directly involved in the temperature regulation of the boiler water.