The Fulton Boiler 2-40-001421 Low Water Cut-Off Relay is a critical safety component designed for use in Fulton steam and hot water boilers. It monitors water levels within the boiler and automatically interrupts burner operation if water drops below safe limits, preventing overheating and equipment damage. https://www.partshnc.com/2-40-001421-fulton-boiler-lwco-relay