Probe and float type low water cut off switches are considered to be

• A. False
• B. True
• C. Inconclusive
• D. Not applicable

Answer: (B)

Probe and float type low water cut off switches are safety devices that automatically shut down a boiler when the water level falls below a safe point. A probe-type uses several electrical probes at different levels to sense water, while a float-type uses a buoyant float connected to a switch. When the water drops too low, the switch opens the circuit and typically stops the burner or gas supply, preventing a dry-firing condition that could cause damage or an explosion. This fail-safe purpose is what makes them classified as safety devices rather than simple controls. Regular testing and proper installation are important to ensure they respond reliably when needed.