What is the primary purpose of a low-water cut-off in a boiler?

• A. To prevent overheating of the boiler
• B. To prevent furnace damage due to low water levels
• C. To control fuel flow into the burner
• D. To maintain consistent pressure in the system

Answer: (B)

The primary purpose of a low-water cut-off in a boiler is to prevent furnace damage due to low water levels. This device is a crucial safety feature that monitors the water level within the boiler. If the water level drops below a specific point, indicating that there may not be enough water to create steam or to absorb excess heat, the low-water cut-off automatically shuts off the burner. This action prevents the boiler from overheating and potentially suffering from severe damage, such as overheating of the furnace or structural failure, which could lead to hazardous situations.

While other components like pressure controls aid in maintaining efficient operation and safety, the low-water cut-off specifically targets the prevention of damage related to insufficient water levels. Therefore, the correct choice reflects the critical operational safety aspect that this control mechanism fulfills within boiler systems.