McDonnell & Miller 343600 Float and Gasket

When you're dealing with a McDonnell & Miller 343600 Float and Gasket (Model SA64-30), you're handling a critical safety component for steam boiler maintenance. This replacement assembly is specifically engineered for the Series 64 Low Water Cut Off and the high-capacity Series 764 controls. In a hydronic heating system, the float must respond instantly to water level fluctuations to prevent dry-firing. This kit includes the precision-weighted replacement float with rod and the required CO-12 head gasket to ensure a high-pressure seal during reassembly.

As an experienced technician, you know that boiler safety controls are only as reliable as their mechanical integrity. Over time, floats can become water-logged or pitted, and gaskets eventually fail under thermal cycling. The SA64-30 Float Assembly is built for heavy-duty residential, commercial, or industrial applications with a maximum boiler pressure of 50 psi. During installation, it is professional best practice to thoroughly scrape the flange surfaces of the control body to avoid leaks. Integrating this genuine McDonnell & Miller part maintains the operational calibration of your low water cut-off, protecting the heat exchanger from catastrophic failure.

• Direct OEM Compatibility: Specifically designed as the drop-in float and gasket for 64 Series and 764 units, eliminating the need for field modifications.
• Complete Replacement Kit: Includes the 343600 float, threaded rod, and the specialized CO-12 gasket for a comprehensive boiler repair.
• High-Pressure Reliability: Rated for systems up to 50 psi, ensuring stable performance in diverse steam and hot water environments.
• Critical Safety Compliance: Essential for restoring the dual precision switches' ability to signal an electric water feeder or trigger a burner cut-off.

Which models are compatible with the McDonnell & Miller 343600?
This assembly is the standard SA64-30 replacement for the Series 64 and Series 764 Low Water Cut Off (LWCO) units used in steam and hot water boilers.

What are the signs that a float assembly needs replacement?
If the burner stays on during a blow-down test or if you notice water inside the float during an annual inspection, the mechanical assembly is compromised and requires immediate replacement.

Does this kit include the gasket?
Yes, the SA64-30 package includes the CO-12 head gasket, which should always be replaced whenever the head mechanism is opened to prevent steam leaks.

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.