McDonnell & Miller 69 Low Water Cut-Off 153900

Original price was: $499.88.Current price is: $347.61.

5 in stock

SKU: 38311 Category:


The McDonnell & Miller 69 Low Water Cut-Off 153900, also known as model number 69 or MH1070 in some references, is a popular choice for protecting steam boilers from the dangers of low water conditions. Here’s a breakdown of its key features and benefits:


  • Automatically shuts down the boiler burner if the water level falls below a safe threshold, preventing overheating and potential explosions.

Operating Principle:

  • Float-activated: A float inside the boiler rises and falls with the water level, triggering a switch when it drops too low.
  • Dual 120-volt switches: One for low water cut-off (boiler shutdown) and the other for alarm or electric water feeders (optional).
  • Maximum pressure of 20 psi: Suitable for residential and commercial low-pressure steam boiler applications.


  • For boilers of any steaming capacity: Offers versatility for various boiler sizes.
  • 4-1/8″ insertion length: Fits comfortably into 2-1/2″ NPT boiler side tappings.
  • Packless bellows: Eliminate potential leak points for increased safety and reliability.
  • Adjustable BX outlet: Adapts to different installation configurations.
  • Dual precision switches: Ensure reliable operation of both the low water cut-off and optional alarm or feeder functions.


  • Enhanced safety: Protects your boiler from the dangers of low water and potential explosions.
  • Reliable performance: Proven design and robust construction ensure years of dependable service.
  • Versatility: Compatible with various boiler types and capacities.
  • Additional control options: Dual switches allow for alarm or feeder activation on low water conditions.
  • Ease of installation: Adjustable outlet and packless bellows simplify setup.

Things to consider:

  • Compatibility: Choose the model with the appropriate pressure rating for your boiler.
  • Installation: Proper installation by a qualified boiler technician is crucial for safety and optimal function.
  • Maintenance: Regular inspection and testing are necessary to ensure the LWCO is working correctly.

Overall, the McDonnell & Miller 69 Low Water Cut-Off 153900 is a valuable safety device for your steam boiler. Its reliable performance, versatility, and ease of use make it a popular choice for protecting your boiler and ensuring safe operation.

Additional information

Weight 4.21 lbs


There are no reviews yet.

Only logged in customers who have purchased this product may leave a review.