Massachusetts 2nd Class Fireman's Exam 2025 – 400 Free Practice Questions to Pass the Exam

The low-water cutoff is a crucial component in preventing a boiler from running dry. Its primary function is to detect the water level within the boiler. When the water level drops below a certain threshold, the low-water cutoff automatically shuts off the burner, preventing overheating and potential damage to the boiler. Without this mechanism, a boiler can overheat as it continues to operate without sufficient water, leading to failures or catastrophic explosions.

Other options have important functions but do not directly address the issue of running the boiler dry. The feed pump is responsible for supplying water to the boiler, but if there is no low-water cutoff in place, the boiler could still run dry if the water level drops unexpectedly. The safety valve is designed to relieve excess pressure and prevent explosions, while the pressure gauge provides information about the internal pressure of the boiler, but neither of these options has the specific role of monitoring and safeguarding against low water levels. Therefore, the low-water cutoff is an indispensable safety feature that directly prevents the risks associated with a boiler running dry.