1/2" Bronze Combination Fill and Backflow Preventer Valve , 15 PSI, Sweat x Thread

Watts 386462 – 1/2" Bronze Fill Valve with Integrated Backflow Preventer

The Watts 386462 combination valve integrates a high-performance boiler fill valve with a dependable backflow preventer, making it ideal for residential and light commercial hydronic heating systems. This pre-assembled unit simplifies installation while ensuring compliance with plumbing codes for system protection and safe water supply operation.

Integrated Design for Maximum Efficiency

This combination valve includes two trusted components: the Watts Model 1156F pressure-reducing valve and the Model 9D backflow preventer. Together, they deliver regulated system pressure and backflow protection in one compact assembly—reducing time on the job and minimizing leak points.

Key Features and Benefits

• Model 1156F Pressure Regulator – Automatically maintains system pressure between 10–25 psi, with a factory setting of 15 psi.
• Model 9D Backflow Preventer – Prevents backpressure and backsiphonage from contaminating the potable water supply.
• Bronze Body Construction – Ensures corrosion resistance and durability in demanding boiler room conditions.
• High Capacity Fill Rate – Designed to handle rapid system fill and purging, streamlining the commissioning process.
• 1/2” Union Solder x NPT Outlet – Offers flexibility for both copper sweat and threaded piping configurations.

Technical Specifications

• Connection Size: 1/2"
• Pressure Rating: Up to 100 PSI inlet; regulated to 15 PSI (adjustable)
• Inlet/Outlet: Union solder inlet x female NPT outlet
• Materials: Bronze body, stainless steel springs, EPDM internals
• Standards: ASSE 1003, CSA B64.3, and ANSI code compliant

Installation Considerations

This unit is factory assembled for fast, secure installation, but due to the safety function of the backflow device and local code requirements, professional installation is highly recommended. Proper orientation, system flushing, and pressure verification should be completed before operation. The unit is designed for vertical installation above the boiler fill point.

Contractor Insight

Watts’ integrated solution helps streamline system setups and meets code without piecing together multiple components. Its field-adjustable regulator saves time during balancing, and the integrated backflow assembly ensures safe isolation from domestic water lines. A reliable choice for new installs and boiler upgrades alike.