Description
Overview
The Xylem-McDonnell & Miller 63-B-M (Part Number 143300) is a mechanical low water cut off designed to protect hot water and steam boilers from the dangers of low water conditions. Featuring a manual reset mechanism, this control requires deliberate operator intervention before the boiler can be restarted after a low water event — providing an added layer of safety and accountability. The integrated float block design ensures reliable, time-tested water level sensing without the need for external probes or electronic components.
Key Features
- 1″ NPT connection for straightforward installation on standard boiler tapping
- 50 PSI maximum boiler pressure rating — suitable for residential and light commercial hot water and steam boiler applications
- Manual reset operation — requires deliberate reset after a low water event, preventing automatic restart and ensuring the cause is addressed before resuming operation
- Mechanical float block design — proven, durable sensing technology with no electronic components to fail
- Compatible with both hot water and steam boiler systems
- Part Number 143300 for easy cross-reference and ordering
Application
The 63-B-M is ideal for use on residential and light commercial hot water and steam boilers where a dependable, manually-reset low water cut off is required. It is designed to shut down the burner when water level drops below a safe threshold, protecting the boiler from damage caused by dry firing.
Specifications
- Brand: Xylem-McDonnell & Miller
- Model: 63-B-M
- Part Number: 143300
- Connection Size: 1″ NPT
- Maximum Boiler Pressure: 50 PSI
- Reset Type: Manual Reset
- Sensing Method: Mechanical Float Block
- Application: Hot Water and Steam Boilers
