McDonnell & Miller 764 Boiler Low Water Cut-Off

The McDonnell & Miller 764 Boiler Low Water Cut-Off delivers reliable protection for steam and hot-water boilers. This heavy-duty mechanical cut-off prevents dangerous low-water conditions, safeguarding equipment and operations. With a 2-1/2 inch threaded port and a compact 6.5-inch height, it fits a wide range of boiler applications—from residential to commercial and industrial systems.

Engineered for 120/240 VAC operation, it supports full-load current of 7.4 A at 120 V and 3.7 A at 240 V, with locked-rotor values of 44.4 A at 120 V and 22.2 A at 240 V. The device handles steam and hot-water media and carries UL, CSA, and FM listings for safe, compliant performance in diverse environments. Designed for pressures up to 50 PSI, it remains dependable across residential through industrial boiler rooms.

• Port connection: 2-1/2" threaded
• Actuation: Mechanical
• Construction: Heavy-duty boiler low-water cut-off
• Height: 6-1/2"
• Media: Steam and hot water
• Applications: Residential, commercial, industrial
• Standards: UL, CSA, FM