Washing Machine Outlet Boxes

34 washing machine outlet boxes and valves from Sioux Chief (13), Oatey (13), LSP Products (6) and Arrowhead Brass (2) — copper sweat, MIP, F1807 and F1960 PEX and push-connect, in standard and fire-rated bodies, assembled and unassembled.

Match the box to the pipe you are actually running. F1807 is crimp and clamp PEX; F1960 is cold-expansion PEX, the Uponor ProPEX system. The fitting profiles are different and the two do not interchange — this is a return, not something an adapter solves. Copper bodies come in sweat and MIP, and push-connect is the option where the wall is already closed and soldering is not on the table.

The hammer arrestor is the part that stops the bang. A washer’s solenoid valve closes in milliseconds and the moving column of water behind it has nowhere to go; the shock runs back up the branch and works every joint on the way. Most boxes here carry arrestors built in — Oatey’s Quadtro and MODA, Sioux Chief’s OxBox with Rester, the LSP Switch Hitter and Kahuna. A box without them costs a few dollars less and is the wrong place to save it on a washer line.

Fire-rated is not a nicer version of the same box. Where the box lands in a rated assembly — a party wall, a corridor, a unit separation in multifamily — the box itself has to be fire-rated or it opens a hole straight through the rating. Sioux Chief’s firerated OxBox and Oatey’s fire-rated MODA are built for that; a standard body in the same opening is a failed inspection.

Quarter-turn ball valves shut cleanly and stay serviceable for years. A single-lever box closes hot and cold together in one motion, which is what you want where the machine gets shut off between uses rather than left under pressure. Unassembled boxes ship flat and cost less to stock; assembled saves the time at the wall.

The two Arrowhead Brass valves are the replacement piece for when the box is fine and the valve is not — 1/2" FIP or 1/2" compression inlet to 3/4" male hose thread, lead free.

Related: utility sinks and laundry tubs, laundry faucets, PEX fittings, supply and outlet boxes and the full laundry range.

Frequently asked questions

Which washing machine box do I need for PEX?

Match the box to the PEX system: F1807 boxes are for crimp and clamp PEX, and F1960 boxes are for cold-expansion PEX such as Uponor ProPEX. The two are not interchangeable.

Do I need a box with hammer arrestors?

It is a good idea on a washer line. A washer valve closes quickly, and the arrestor absorbs the shock that causes banging pipes.

When is a fire-rated box required?

When the box goes into a fire-rated wall assembly, such as a wall between units. Check the local code and the wall rating.

Can I replace only the valve?

Yes, where the box is in good shape. The Arrowhead Brass WM50F (1/2" FIP) and 221CCLF (1/2" compression) are lead-free washing machine valves with a 3/4" hose thread outlet.