WATTSSKU: 39908

WATTS® 0386463 B911T-M3 Combination Fill Valve and Backflow Preventer

$284.79
In stock (1009)

Simplify boiler feed water management with this pre-assembled combination fill valve and backflow preventer, purpose-built for commercial and residential hydronic heating systems. By combining a bronze backflow preventer (Model 9D) and a bronze feed water pressure regulator (Model 1156F) into a single unit, this valve delivers automatic make-up water to the boiler while protecting your potable water supply from backflow whenever supply pressure drops below system pressure.

The high-capacity design means faster system filling and purging, saving time on installation and startup. Installed directly in the boiler feed line, it's engineered to handle the demands of everyday hydronic heating applications with a compact 1/2" union NPT inlet and NPT threaded outlet for straightforward installation into existing piping configurations.

Shipping policy

Orders placed by 2:00pm EST will ship same day, except on holidays.

More Details

Product overview
  • Combination unit: bronze backflow preventer (Model 9D) + bronze pressure regulator (Model 1156F), pre-assembled for easy installation
  • Flexible mounting - installs in horizontal or vertical orientation
  • Automatically feeds make-up water to the boiler as needed
  • Prevents backflow when supply pressure falls below system pressure
  • High-capacity fill valve for quick system filling and purging
  • Built-in strainer screen helps protect internal components from debris
  • Easy service accessibility for maintenance and inspection
  • Threaded connections (1/2" union NPT inlet x NPT threaded outlet) for straightforward installation
  • Durable all-bronze body construction for long service life
Specifications
Manufacturer Part Number 0386463
UPC 98268918533
Overall Dimensions 7-1/2 in W x 5-11/16 in H
Material n/a
Domestic or Import n/a
End Style n/a
Type n/a
ADA Compliance n/a
Warning n/a
Standards and Approvals PROP65: This product can expose you to chemicals including lead which is known to the State of California to cause cancer and birth defects or other reproductive harm.
Resources
Delivery & Returns

Orders will ship same day if received by 2pm EST.

Upcoming holiday closures: September 7, 2026

All returns are inspected on receipt; credit is issued after condition is confirmed. Credit is issued only for items returned in original, saleable condition after inspection.

FINAL SALE ITEMS ARE NOT ELIGIBLE FOR RETURNS OR EXCHANGES.

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