McDonnell & Miller 53-HD Control

Upgrade or restore your boiler's mechanical water feeder with the McDonnell & Miller 53-HD Head Mechanism. Designed specifically for low pressure steam and hot water boilers, this heavy-duty Series 53 replacement part (Part Number 137000) provides proportional feed action to maintain safe water levels in systems larger than 5,000 sq. ft. As a head mechanism only, this unit allows for a direct swap onto your existing float chamber without needing to tear out your 1" NPT equalizing lines. It is rated for a 75 PSI max vessel pressure and a water supply pressure up to 150 PSI. The 137000 includes a quick-change replaceable cartridge valve and strainer, simplifying boiler water level control maintenance for busy contractors. This mechanical feeder ensures a constant water supply, preventing the dry-firing of high-capacity heating systems while meeting the demands of high-head pressure applications.

• Direct Replacement: Fits Series 53 and 53-2 float chambers for efficient field repairs.
• Maximum Durability: Engineered for vessel pressures up to 75 PSI, surpassing standard model limits.
• Simplified Maintenance: Features a replaceable cartridge valve and strainer for rapid servicing.
• High Capacity: Optimized for large-scale residential and commercial boilers exceeding 5,000 sq. ft.
• Proportional Feed: Delivers precise automatic water makeup to prevent water level fluctuations.

Common Questions

Can I upgrade this to include a low water cut-off?
Yes, the 53-HD head mechanism is field-upgradable. By adding a No. 2 switch, you can integrate a low water cut-off function to provide dual protection for your boiler system.

Does this include the float chamber?
No, the 137000 is the head mechanism only. It is designed to be bolted onto the existing float chamber of a McDonnell & Miller Series 53 unit, which saves time on piping during a replacement.

What is the maximum water temperature for this feeder?
This unit is designed to handle a maximum inlet water temperature of 120°F (49°C), ensuring reliable performance with standard city water or cold-water feed setups.

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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.