Minnesota Boiler License Practice Exam

What is the purpose of the low water cut out on a steam or hot water boiler?

1. Add water to the boiler

2. Shut off the burner when low water conditions arise

3. To relieve all excess pressure

4. To remove excess water from the boiler

The correct answer is: Shut off the burner when low water conditions arise

The low water cut out serves a critical safety function in the operation of steam and hot water boilers. Its primary purpose is to shut off the burner when low water conditions arise. This action is essential because if the water level in the boiler drops too low, the boiler can overheat, which could lead to severe damage or even catastrophic failure. When the low water cut out detects that the water has reached a pre-determined low level, it automatically interrupts the fuel supply to the burner, thereby preventing the boiler from operating without sufficient water. This protective measure ensures the integrity and safety of the boiler system, as it helps to avoid dry firing, which can result in overheating of the boiler components. In contrast, adding water to the boiler, relieving excess pressure, or removing excess water do not directly relate to the function of the low water cut out. These actions are managed by other components and systems within the boiler operation and do not address the critical safety concern of low water levels.