Series 157S – Low Water Cut-Off/Pump Controllers

McDonnell & Miller : Combination Low Water Cut-Offs/Pump Controllers :

Features and Benefits

  • For residential, commercial and industrial low or high
  • pressure boiler applications
  • For boilers of any steaming capacity
  • Monel bellows provides corrosion resistance
  • Float chamber with integral water column provided
  • Snap action for high temperature service
  • – 1 Single pole, single throw switch for pump control
  • – 1 Single pole, double throw switch for low water
  • cut-off and alarm actuation
  • Optional features
  • – Manual reset
  • – Integral conductance probes for additional levels and
  • greater operating differential-Model 157S-RBP-MD
  • – 1″ or 11⁄4″ NPT equalizing tappings
  • – 1⁄2″ or 3⁄4″ NPT tappings for gauge glass/tri-cock
  • installations
  • – BSPT threads
  • Maximum pressure 150 psi (10.5 kg/cm2)
  • For new electronic 150E Series see page 37
  • Model 157S-MD
  • Maximum differential operation
  • – Prevents nuisance burner shutdowns in low pressure
  • applications
  • – Maximum operating pressure 50 psi (3.5 kg/

Installation/Operation Manuals

Parts Lists


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