McDonnell & Miller model number 42S-A is a combination float-operated low water cut-off and pump controller with quick hook-up fittings for steam boilers. This control features an automatic reset and two 120 volt, bi-metal, two-wire, single pole, single throw snap switches. Its maximum pressure is 50 psi and it has a tapped 1" FIP connection.
McDonnell & Miller, a unit of ITT Industries, is a leader in engineering and manufacturing boiler controls, liquid level controls, low-water cutoffs, and flow switches for steam and hot water boilers in industrial, commercial, and building trade applications. McDonnell & Miller specializes particularly in boiler controls and power switches.