McDonnell & Miller 93-HDLS Controller

The McDonnell & Miller 93-HDLS (Part 162402) is a specialized head mechanism only assembly designed for critical steam boiler water level control. This combination low water cut-off and pump controller is engineered for high-pressure applications with a maximum steam pressure of 150 PSI. Built for heavy-duty commercial and industrial environments, the 93-HDLS utilizes a robust mechanical float-operated mechanism to provide reliable boiler pump control and essential low-water protection. As a "Less Switch" (LS) configuration, it is intended as a direct drop-in replacement head for existing Series 93 installations where the mercury switch or snap-action switch is already sourced or needs separate specification. This unit ensures precision differential pressure management and maintains optimal boiler water levels to prevent dry-fire conditions. For contractors performing system retrofits, this genuine OEM mechanical level control ensures seamless compatibility with Series 93 boiler controllers, maintaining the integrity of the original safety certification and HVAC system reliability.

Key Benefits

• Direct Series 93 Compatibility: Engineered specifically for replacement head mechanism applications in 150 PSI steam systems.
• Industrial Build Quality: Features a high-pressure float assembly designed to withstand the thermal stress of industrial steam cycles.
• Precise Level Management: Provides accurate pump on/off setpoints to prevent short-cycling and extend the life of feeder pumps.
• Enhanced System Safety: Functions as a primary or secondary low water cut-off (LWCO) to protect the pressure vessel.
• Reduced Downtime: The head mechanism only design allows for rapid field replacement without disturbing the existing pipework or casting.

Common Questions

Is the 93-HDLS compatible with all Series 93 castings?
Yes, it is designed to fit standard Series 93 bodies, provided the system requirements do not exceed the 150 PSI rating.

Does this unit include the electrical switches?
No, the "Less Switch" (LS) designation indicates this is the mechanical head and float mechanism only; No. 5 switches or No. 7 switches must be ordered separately or salvaged from the previous unit.

Can this be used for water heating applications?
This specific McDonnell & Miller controller is optimized for steam boiler service and pump control logic rather than hydronic heating expansion tanks.

This item is not eligible for free shipping.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.