Skip to content
  • 🚚 No shipping fees, more savings 🚚
  • 🚚 No shipping fees, more savings 🚚
Outlet Hvac Motive StoreOutlet Hvac Motive Store
  • Menu
    • No products in the cart.

      Return to shop

  • Cart

    No products in the cart.

    Return to shop

  • HVAC Components
    • Crankcase Heaters
    • Compressors
    • Heat Exchangers
    • Hard Start Kits
    • Furnace & Air Handlers
    • Cooling Filter Dryers
    • Service Tools & Parts
  • Ignition & Combustion Components
  • Pumps & Circulators
  • Capacitors
  • HVAC Hardware & Parts
    • Hydronic Hardware & Parts
Home / HVAC Hardware & Parts / Hydronic Hardware & Parts
Sale!
McDonnell & Miller Series 157 Low Water Cut-off/Pump Controller With Maximum Differential 157S-MD

McDonnell & Miller Series 157 Low Water Cut-off/Pump Controller With Maximum Differential 157S-MD

$600.00 Original price was: $600.00.$97.99Current price is: $97.99.

SKU: McDonnell & Miller WBB916121 Categories: HVAC Hardware & Parts, Hydronic Hardware & Parts Tags: 150 psi, 157, 173603, HVAC & Fans, Low Water Cut-off/Pump Controller With Maximum Differential, McDonnell & Miller, Residential, Commercial And Industrial Low Or High Pressure Boiler Applications
  • Sustainable materials, for a better tomorrow.
  • Efficiency meets excellence in customer care.
  • Fast, friendly, always here to help.
  • Buy Quality, Live Better
Browse
  • HVAC Components
    • Capacitors
    • Compressors
    • Cooling Filter Dryers
    • Crankcase Heaters
    • Furnace & Air Handlers
    • Hard Start Kits
    • Heat Exchangers
    • Ignition & Combustion Components
      • Combustion Air Systems
      • Flue Gas Vent Pipes & Supports
      • Fuel Valves
      • Gas Ignition & Pilots
      • Gas Regulators
      • Venting Control Kits
    • Pumps & Circulators
      • Circulators
      • Condensate Pumps
      • Expansion Tanks & Vents
      • Flanges, Seals & Mounts
      • Fuel Oil Pumps
      • Pump & Circulator Accessories
    • Service Tools & Parts
      • HVAC Cleaning Equipment
      • HVAC Thermometers
      • Installation & Maintenance Tools
      • Refrigerant Leak Detectors
      • Refrigerant Manifolds & Gauges
      • Refrigerant Recovery Tools
  • HVAC Hardware & Parts
    • Hydronic Hardware & Parts
  • Uncategorized
  • Description
  • Additional information
  • Reviews (0)
McDonnell & Miller Series 157 Low Water Cut-off/Pump Controller With Maximum Differential 157S-MD

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 1-1/4″ NPT equalizing tapings – 1/2″ or 3/4″ NPT tapings for gauge glass/tri-cock installations . BSPT threads. Maximum pressure 150 psi (10. 5 kg/cm2)Model 157S-MD Maximum differential operation – Prevents nuisance burner shutdowns in low pressure applications operating less than 50 psi (3. 5 kg/cm2). Made in the USA.

Weight

39.7 lbs

Type

Low Water Cut-off/Pump Controller With Maximum Differential

Manufacturers Part Number

173603

Series

157

For Use With

Residential, Commercial And Industrial Low Or High Pressure Boiler Applications

Max Pressure

150 psi

Brand

McDonnell & Miller

Warranty

1 yr

Reviews

There are no reviews yet.

Be the first to review “McDonnell & Miller Series 157 Low Water Cut-off/Pump Controller With Maximum Differential 157S-MD” Cancel reply

Related products

Sale!
Drain Pump Kit For 1.1 & 1.5 Ton Global Industrial™ Portable AC's
Quick View

HVAC Components

Drain Pump Kit For 1.1 & 1.5 Ton Global Industrial™ Portable AC’s

$288.95 Original price was: $288.95.$96.99Current price is: $96.99.
Sale!
National Refrigeration Products NRP NC1000 Refrigerant Recovery Cylinder, 1000 Lbs With Float Gauge
Quick View

HVAC Components

National Refrigeration Products NRP NC1000 Refrigerant Recovery Cylinder, 1000 Lbs With Float Gauge

$579.00 Original price was: $579.00.$95.99Current price is: $95.99.
Sale!
SpeedClean CJ-125 - CoilJet®; Portable HVAC Coil Cleaner System, 125 PSI, 0.6 GPM
Quick View

HVAC Cleaning Equipment

SpeedClean CJ-125 – CoilJet®; Portable HVAC Coil Cleaner System, 125 PSI, 0.6 GPM

$454.00 Original price was: $454.00.$92.99Current price is: $92.99.
Sale!
Maxitrol 1" Certified Line Regulator with Imblue Technology 325-5BL-1, Up To 325,000 BTU
Quick View

Gas Regulators

Maxitrol 1" Certified Line Regulator with Imblue Technology 325-5BL-1, Up To 325,000 BTU

$82.95 Original price was: $82.95.$58.07Current price is: $58.07.
Sale!
Maxitrol 1" Lever Acting Regulator with Vent Limiter 325-5V-1 Up To 325,000 BTU
Quick View

Gas Regulators

Maxitrol 1" Lever Acting Regulator with Vent Limiter 325-5V-1 Up To 325,000 BTU

$58.95 Original price was: $58.95.$41.27Current price is: $41.27.
Sale!
Mastercool® 63010 50 lb D.O.T. Refrigerant Recovery Tank Without Float Switch 1/4" FL-M
Quick View

HVAC Components

Mastercool® 63010 50 lb D.O.T. Refrigerant Recovery Tank Without Float Switch 1/4" FL-M

$167.95 Original price was: $167.95.$96.99Current price is: $96.99.
Sale!
Supco Commercial Condensate Pan 2.5 Qt, 120 V, 800 Watts
Quick View

HVAC Components

Supco Commercial Condensate Pan 2.5 Qt, 120 V, 800 Watts

$138.95 Original price was: $138.95.$96.99Current price is: $96.99.
Sale!
Supco Commerial Condensate Evaporator Pan 4.5 Qt 120V 1000W
Quick View

HVAC Components

Supco Commerial Condensate Evaporator Pan 4.5 Qt 120V 1000W

$157.95 Original price was: $157.95.$95.99Current price is: $95.99.
MY ACCOUNT
  • Cart
  • Checkout
  • My account
  • Wishlist
ABOUT US
  • About Us
  • FAQ
  • Returns & Exchanges
  • Delivery
  • Contact Us
LEGAL
  • Privacy Policy
  • Payment Method
  • Shipping & Returns
  • Term and Conditions
Signup for Newsletter

We will keep you up to date with all the latest news and exclusive promotions.

    Copyright 2026 © www.hvacmotive.com
    • HVAC Components
      • Crankcase Heaters
      • Compressors
      • Heat Exchangers
      • Hard Start Kits
      • Furnace & Air Handlers
      • Cooling Filter Dryers
      • Service Tools & Parts
    • Ignition & Combustion Components
    • Pumps & Circulators
    • Capacitors
    • HVAC Hardware & Parts
      • Hydronic Hardware & Parts
    • Login

    Login

    Lost your password?

    Register

    Your personal data will be used to support your experience throughout this website, to manage access to your account, and for other purposes described in our privacy policy.