Description
The McDonnell & Miller 369 (Part Number 155300) is a dependable, mechanically operated low water cut off designed specifically for steam boiler protection. With an auto-reset function, this unit automatically restores boiler operation once safe water levels are re-established — eliminating the need for manual intervention and reducing downtime.
Key Features
- Auto-reset mechanical operation — no manual reset required after water level is restored
- 2-1/2″ NPT connection for straightforward installation on standard boiler tappings
- 1-3/4″ insertion length for accurate water level sensing within the boiler
- 20 PSI maximum steam pressure rating — suitable for low-pressure steam heating systems
- Designed for steam boiler applications to prevent dry-fire damage and protect heating equipment
- Rugged mechanical design for long-term reliability in demanding boiler room environments
Product Specifications
- Brand: McDonnell & Miller (Xylem)
- Model / SKU: 369
- Part Number: 155300
- Connection Size: 2-1/2″ NPT
- Insertion Length: 1-3/4″
- Maximum Steam Pressure: 20 PSI
- Reset Type: Automatic
- Application: Steam Boilers
Application
The McDonnell & Miller 369 is engineered for low-pressure steam heating boilers found in residential and light commercial settings. It continuously monitors boiler water levels and cuts off the burner circuit when water drops below the safe operating threshold, protecting the boiler from potentially catastrophic dry-fire conditions. The auto-reset feature makes it ideal for installations where unattended operation is required, restoring normal burner function automatically once adequate water levels return.
Why Choose McDonnell & Miller
McDonnell & Miller, a brand under Xylem, has been a trusted name in boiler protection controls for over a century. Their low water cut offs are widely specified by engineers and relied upon by HVAC professionals for their proven mechanical simplicity, durability, and consistent performance in steam and hot water heating systems.
Reviews
There are no reviews yet.