What is the primary function of a low water cutoff in a boiler?

The primary function of a low water cutoff in a boiler is to shut down the boiler if water levels are too low. This mechanism is crucial for ensuring the safe operation of a boiler system. When the water level falls below a certain point, the low water cutoff automatically stops the burner and prevents the boiler from operating without sufficient water. Operating a boiler without enough water can lead to overheating, damage to the boiler components, or even a catastrophic failure, as the boiler relies on water to absorb and carry away heat.

In contrast, other roles mentioned in the choices, such as regulating water temperature, increasing water pressure, or enhancing combustion efficiency, are managed by different components in the boiler system. These functions, while important, do not relate to the critical safety feature that the low water cutoff provides. Therefore, ensuring that the boiler is safely shut down when water levels are low is its primary and most vital function.