Backflow Preventer ¾” Brass Dual Check Valve

Backflow Preventer 3/4" is a required component of the Outdoor Boiler Fill Kit.  Connections are FNPT.

Codes require a backflow preventer when connecting an outdoor boiler (or any external water tank) to your domestic water supply to prevent contaminants from entering (or "Backflowing") your domestic water supply. This prevents non-potable water and possibly harmful chemicals from coming out your shower head or into your pot of pasta!