Xylem-McDonnell & Miller 157S-R Combination Low Water Cut-Off & Pump Controller | SKU 157S-R

Description

The Xylem-McDonnell & Miller 157S-R (Part Number 176220) is a combination low water cut-off and pump controller engineered to protect steam boilers from dangerous low-water conditions while simultaneously managing pump operation. Featuring a snap-acting SPDT (Single-Pole, Double-Throw) switch and alternate tappings for flexible installation, the 157S-R delivers reliable, responsive boiler protection in a single, compact unit.

Key Features

• Combination low water cut-off and pump controller in one unit
• Snap-acting SPDT switch for fast, positive switching response
• Alternate tappings for versatile boiler piping configurations
• Float-operated mechanism for accurate water level sensing
• Designed for steam boiler low-water protection and pump control
• Durable cast iron body for long service life in demanding boiler room environments
• Easy-to-service design with accessible internal components

Application

The 157S-R is ideal for use on steam heating boilers where both low water cut-off protection and automatic pump control are required. The alternate tappings allow the control to be installed in a variety of boiler tapping configurations, making it a versatile solution for new installations and replacements alike. The snap-acting SPDT switch ensures reliable circuit interruption to the burner when water drops below the safe operating level, preventing costly boiler damage.

Product Specifications

• Part Number: 176220
• SKU: 157S-R
• Switch Type: Snap-Acting SPDT (Single-Pole, Double-Throw)
• Function: Combination Low Water Cut-Off and Pump Controller
• Tappings: Alternate Tappings Included
• Application: Steam Boilers
• Brand: Xylem-McDonnell & Miller

Why Choose McDonnell & Miller?

McDonnell & Miller, a brand of Xylem, has been a trusted name in boiler safety controls for over a century. The 157S-R continues that legacy of quality and reliability, providing HVAC professionals and boiler technicians with a dependable control that meets the demands of modern steam heating systems.