Mcdonnell & Miller Series 69 – Built-In Low Water Cut-Offs

The McDonnell & Miller low water cut-off is used in steam and hot water boilers to automatically shut off the burner if the water level drops below a safe point, preventing dry-fire damage. It mounts in 2½" NPT boiler side tappings and is essential for boiler safety in commercial and industrial heating systems.

This McDonnell & Miller low water cut-off is designed for mounting in 2½" NPT boiler side tappings. It features a packless construction and offers insertion lengths of 1-3/16", 4-1/8" (30–105 mm). The exact model and pressure/temperature ratings should be verified from the manufacturer's datasheet for your specific application.

3G Electric supplies McDonnell & Miller low water cut-offs to customers in Singapore. We source these safety devices globally and handle all logistics, customs clearance, and delivery to your facility. Contact our team for a quotation and lead time on your required insertion length.

Install the McDonnell & Miller low water cut-off into a 2½" NPT boiler side tapping at the recommended water line level. Ensure the insertion length matches your boiler's dimensions (available from 1-3/16" to 4-1/8"). Follow the manufacturer's wiring diagram for electrical connections and test the cut-off function after installation.