A washing machine outlet box with a water hammer arrestor combines hot and cold shutoff valves, hose connections, and a drain opening in one recessed unit. The arrestor is designed to absorb pressure shock when a washer valve closes, which may help reduce banging pipes. The best choice depends on your supply-pipe material and connection method: a box made for PEX crimp fittings is not interchangeable with one designed for soldered copper or push-to-connect installation.
Below, the five options differ in their pipe connections, installation features, and the information available about their design. Check the box’s exact fittings and your local plumbing requirements before you buy.
Table of Contents
Quick Comparison
| Product | Supply connection | Standout feature | Best suited for |
|---|---|---|---|
| SECKWHALE Outlet Box with Stainless Steel Arrestor | 1/2-inch MIP or sweat | Quarter-turn valves; central and side drains | Installations using compatible threaded or sweat connections |
| SECKWHALE PEX Crimp Outlet Box | 1/2-inch PEX crimp | Stainless steel arrestor; labeled controls | Compatible PEX crimp systems |
| SharkBite Push-to-Connect Outlet Box | Push-to-connect | Works with PEX, copper, CPVC, and PE-RT | Those seeking a tool-free connection method |
| Sioux Chief Ox Box with PEX Crimp Connections | 1/2-inch female PEX | Water hammer arrestors | Projects specifically requiring PEX crimp connections |
| Sioux Chief Oxbox with Minister Arresters | Not specified in the provided details | Separate supply and drainage boxes | Layouts that need flexible box placement; confirm water-use suitability |
Our Picks: Best Washing Machine Box With Hammer Arrestor reviews
1. SECKWHALE Outlet Box for MIP or Sweat Connections
This SECKWHALE box is designed for supply lines using 1/2-inch MIP or sweat connections, with 3/4-inch MHT outlets for washing machine hoses. Its built-in stainless steel water hammer arrestor is intended to absorb pressure shock and help reduce pipe noise. The box also has quarter-turn hot and cold shutoff valves.
One useful detail is the choice of central or side drain openings, which can help with different drain-pipe layouts. The recessed box has a snap-on frame, and the product information describes it as suitable for inverted installation. Its brass components are identified as C46500 brass, and the maker states that the box meets UPC and NSF requirements.
This is a sensible option when the supply connections match its MIP or sweat design. It is not the simplest pick for someone looking for a push-fit connection, and the connection type should be confirmed before rough-in. As with any outlet box, the installation still needs to match the plumbing plan and local code.
Pros:
- Includes an integrated water hammer arrestor and quarter-turn shutoffs.
- Offers central and side drain openings.
- Supports 1/2-inch MIP or sweat supply connections.
- Recessed design includes a snap-on frame.
Cons:
- Not a push-to-connect option.
- Requires careful confirmation of the supply-side connection type.
Verdict: Choose this box if your plumbing uses compatible MIP or sweat connections and you want multiple drain-position options in one unit.
2. SECKWHALE Outlet Box for PEX Crimp Systems
This SECKWHALE model is made for 1/2-inch PEX crimp connections and has 3/4-inch MHT outlets for washer hoses. It includes a stainless steel water hammer arrestor and quarter-turn hot and cold shutoff valves. The manufacturer specifies that it is not compatible with expansion-style PEX fittings.
The box has a recessed design, a snap-on frame, and support for inverted installation. The product details also call out clear text labels, which can make it easier to identify the hot and cold controls during installation or later shutoff. C46500 brass is used for the box’s brass components, and the manufacturer states that the product meets UPC and NSF requirements.
This is a focused choice for a home with a compatible PEX crimp system. A crimping tool is required, so it is not a tool-free alternative. If your PEX installation uses expansion fittings, choose another connection style rather than assuming this one will work.
Pros:
- Designed for 1/2-inch PEX crimp connections.
- Includes a stainless steel arrestor and quarter-turn valves.
- Has labeled controls and a snap-on frame.
- Can be installed in an inverted position, according to the product details.
Cons:
- Not compatible with PEX expansion fittings.
- A crimping tool is required to complete the installation.
Verdict: This is a good match for a PEX crimp installation, but skip it if your system uses expansion fittings or you need a tool-free connection.
3. SharkBite Push-to-Connect Box for Multiple Pipe Types
The SharkBite Max combines a washing machine outlet box, quarter-turn shutoff valves, 3/4-inch MHT hose outlets, and a water hammer arrestor. Its push-to-connect fittings are listed for PEX, copper, CPVC, and PE-RT pipe. The product information describes installation without glue, soldering, or crimping.
Its mounting options are a notable advantage: the box can be placed to the left, right, or center of the stud bay, and the listing describes dual or inverted drain installations. The snap-on faceplate is specified for drywall up to 3/4 inch thick. The product is rated for 125 PSI and 200°F, according to its specifications.
Push-to-connect fittings can simplify the connection process, but the pipe must still be prepared and installed correctly. The listed disconnect clip or tongs for removal are sold separately. Compared with the SECKWHALE models, this option emphasizes connection flexibility across several pipe materials rather than a specific crimp or sweat connection.
Pros:
- Push-to-connect fittings are listed for PEX, copper, CPVC, and PE-RT.
- Does not require soldering, glue, or crimping for the connection method described.
- Offers left, right, or center mounting and dual or inverted drain options.
- Includes quarter-turn valves, a faceplate, and a water hammer arrestor.
Cons:
- Disconnect tools are sold separately.
- Its compatibility still depends on matching the pipe type and installation instructions.
Verdict: Pick the SharkBite if your pipe material is compatible and you value a push-to-connect installation with flexible mounting options.
4. Sioux Chief Ox Box with PEX Crimp Connections
This Sioux Chief Ox Box is identified as a washing machine outlet box with water hammer arrestors and 1/2-inch female PEX connections. That makes it a potential fit for projects designed around the specified PEX connection. The available product details are brief, so they do not provide the same level of information about drain positions, faceplate fit, or installation flexibility as some of the other choices here.
Because the listing information does not spell out more installation details, confirm the exact connection requirements, included parts, and fit with your plumbing layout before purchasing. The product data supplied for this model indicates that it is unavailable, so check the current product listing and consider an alternative if it cannot be obtained.
Compared with the SharkBite, this is a more narrowly described PEX option and does not list compatibility with copper, CPVC, or PE-RT. Compared with the SECKWHALE PEX model, its supplied description offers less detail about valves, materials, or box features.
Pros:
- Specifies 1/2-inch female PEX connections.
- Includes water hammer arrestors, according to the product title and description.
- Designed as a washing machine outlet box.
Cons:
- Product details provided are limited.
- Availability may be an issue; confirm the listing before planning around it.
Verdict: Consider this Ox Box only if its PEX connection matches your project and you can confirm the product’s availability and installation details.
5. Sioux Chief Oxbox with Separate Supply and Drain Boxes
This Sioux Chief Oxbox is described as a system with separate boxes for the supply and drainage sides. That layout can offer flexibility when the two systems need to sit in different stud bays. The product details also mention mounting to or over a stud and debris covers intended to help protect the boxes during construction.
The key caution is that the supplied description explicitly says this product is not for potable water use. Since a washing machine’s supply connects to the home water system, do not assume this product is suitable for your installation. Confirm the intended use with the manufacturer and local plumbing requirements before considering it.
The available information also does not specify the supply connection type or give much detail about the included arresters. That makes it harder to compare with the more fully described SECKWHALE and SharkBite boxes. Its separate-box design may suit a specific layout, but the stated water-use limitation is a major reason to verify fit and suitability first.
Pros:
- Separate supply and drainage boxes allow a flexible layout.
- Can mount to a stud or over studs, according to the product details.
- Includes debris covers to help protect the boxes during construction.
Cons:
- The supplied description says it is not for potable water use.
- Connection details and arrester specifications are limited.
Verdict: Do not choose this for a typical washer supply installation unless the manufacturer confirms that its stated water-use limitation does not rule out your intended application.
How to Choose a Washing Machine Box With a Hammer Arrestor
Match the supply connection to your pipe
Start with the pipe material and connection system already planned for your washer. The products here include MIP or sweat connections, PEX crimp fittings, push-to-connect fittings, and a model described as having female PEX connections. These methods are not interchangeable. Check the manufacturer’s specifications and your plumber’s plan rather than choosing by brand name alone.
Check hose outlet size and valve layout
Washer hoses commonly connect to the box’s hot and cold outlets, so confirm that the outlet fitting matches your hoses. Several options here specify 3/4-inch MHT outlets. Also look for accessible shutoff valves. Quarter-turn valves are included on the SECKWHALE and SharkBite models listed above, making it important to position the box so you can reach them after installation.
Consider drain placement and box orientation
The drain opening needs to line up with your planned standpipe and wall layout. The first SECKWHALE model describes both central and side drains, while the SharkBite listing calls out dual or inverted drain installations. Other products provide less information, so confirm the opening location, allowed orientation, and fit before closing the wall.
Understand what the arrestor can do
A water hammer arrestor is designed to absorb pressure shock when a washer valve closes quickly. This can help reduce pipe movement and banging, but it should not be treated as a fix for every plumbing noise. If pipes still shake or make loud sounds, the issue may need diagnosis beyond replacing the outlet box.
Review installation needs and access
Installation methods range from push-to-connect fittings to sweat and PEX crimp connections. A crimp model requires the correct tool, while the SharkBite description lists push-to-connect installation without crimping or soldering. Consider your skills, the tools on hand, and whether a licensed plumber should do the work. Keep the shutoff valves accessible once the washer is in place.
Confirm ratings, standards, and intended use
Read the product specifications for pressure and temperature limits, applicable standards, and intended water use. The SharkBite listing provides pressure and temperature ratings, and the SECKWHALE listings state UPC and NSF compliance. The fifth product’s supplied details say it is not for potable water use, so that limitation should be resolved with the manufacturer before purchase.
Frequently Asked Questions
What does a water hammer arrestor do in a washing machine box?
It is designed to absorb pressure shock when the washer’s water valve closes. This may help reduce banging or shaking in the pipes, though it does not guarantee that all plumbing noise will disappear.
How do I know which outlet box will fit my plumbing?
Identify your supply-pipe material and connection method first. Then match it to the box’s stated fitting type, such as PEX crimp, push-to-connect, MIP, or sweat. If you are unsure, ask a plumber to confirm the connection before buying.
Can I use a PEX crimp box with expansion-style PEX?
Not automatically. The SECKWHALE PEX model specifically says it is not compatible with expansion fittings. Check the exact box and fitting system requirements for any product you consider.
Do all washing machine outlet boxes have the same drain opening?
No. The product details show different drain options, including central, side, dual, or inverted arrangements. Confirm that the chosen box fits your planned drain location and wall framing.
Is a push-to-connect outlet box easier to install?
It can avoid soldering, glue, or crimping for the connection method described by the SharkBite listing. You still need to follow the installation instructions and confirm that your pipe material is compatible. Some removal tools are sold separately.
Can I use the Sioux Chief Oxbox that says it is not for potable water?
Do not assume it is suitable for a standard washing machine water supply. The supplied product information says it is not for potable water use. Contact the manufacturer and check local plumbing requirements before considering it for your installation.
Final Recommendation
For a straightforward choice, match the box to your existing plumbing rather than focusing only on the arrestor. The SharkBite stands out for its listed push-to-connect compatibility with several pipe materials and flexible mounting options. The SECKWHALE models are more specific fits for MIP or sweat connections and PEX crimp systems. Confirm all connection and drain details before ordering, and treat the Sioux Chief model labeled not for potable water with particular caution.
