McDonnell & Miller 64-B Low Water Cut Off 30067439-890 or immediately if the pressure

or immediately if the pressure drop exceeds 10 mbar across the unit

residential models use smaller 1/2" or 3/4" valves

Broad Compatibility: UL-listed for modern refrigerants including R1234ze(E) and R513A

Optimized Steam Generation: Maintains the evaporation efficiency required for precise humidity control in commercial environments

reducing system downtime and labor costs for technicians

McDonnell & Miller 64-B Low Water Cut Off 30067439-890 or immediately if the pressureThe McDonnell & Miller 64 B Low Water Cut Off (Part Number 143800) is a heavy duty mechanical safety control engineered for both hot water and steam boilers. As a veteran grade float type LWCO, this unit provides essential protection against dry firing by interrupting the burner circuit if the water level drops below a safe threshold. It features a robust 1" NPT connection and is rated for a maximum boiler pressure of 50 PSI. The integration of dual