The Xylem-McDonnell & Miller RB-24SE Low Water Cut-Off is a safety control designed to protect compatible boiler systems from operating with insufficient water levels. It monitors the water level and interrupts the burner or heating circuit when the level drops below a safe point, helping prevent overheating and potential equipment damage. Commonly used in steam and hydronic boilers, ... https://www.partshnc.com/rb-24se-xylem-mcdonnell-miller-low-water-cut-off-universal-wiring-harness-24v