What purpose does a flame safeguard serve in boiler operation?

A flame safeguard plays a crucial role in boiler operation primarily by ensuring safety. Its main function is to detect the presence of a flame during the combustion process. If the flame goes out or fails to ignite, the flame safeguard system automatically takes action, such as shutting down the burner or preventing fuel flow. This prevents potential hazardous situations, such as the accumulation of unburned fuel or explosive conditions, thus safeguarding both the equipment and personnel.

The other options, while they pertain to aspects of boiler operation, do not accurately capture the primary role of a flame safeguard. Increasing burner efficiency, regulating water temperature, and monitoring fuel costs are important elements of boiler functionality but are not the direct responsibilities of the flame safeguard system.