Final answer:
The low water cutoff is a safety device on boilers that shuts off the burner to prevent overheating when water levels are too low.
Step-by-step explanation:
The low water cutoff is an automatic electric control that will shut the burner off when the water level is below a safe operating point. This is a critical safety device on a boiler, as it prevents the boiler from operating in a condition that could lead to overheating of the boiler tubes and potential boiler explosion.
The function of the low water cutoff is to measure the water level within the boiler. If the water level falls below a predetermined safe level, the sensor in the cutoff will trigger, causing the burner to be shut off to prevent damage to the boiler system. This ensures that the heating process is halted before the water level becomes dangerously low, safeguarding against heat damage to the boiler's structure and potential hazards to personnel and property.