How To Quiet Pipes With a Water Hammer Arrestor

Banging pipes can be a frustrating and disruptive problem in any home. Referred to as a “water hammer,” this noise occurs when fast-moving water suddenly stops or changes direction, causing a shock wave that rattles pipes. Fortunately, there’s a simple solution: installing a water hammer arrestor. In the video above, This Old House plumbing and heating expert Richard Trethewey demonstrates how to silence noisy pipes using this effective device.

Understanding Water Hammer

Water hammer is a common plumbing issue that can occur in both old and new homes. Over time, the repeated shock can damage pipes, fittings, and appliances.

Causes of Water Hammer

Several factors can contribute to water hammer, including the following:

• Air pockets in the plumbing system, which can form due to improper venting or draining, can lead to noisier pipes.
• High water pressure can exacerbate the problem by increasing the force of the water flow.
• Loose pipes that are not properly secured can move and create noise.
• Quick-closing valves, such as those found in dishwashers and washing machines, can cause sudden stops in water flow.

Effects of Water Hammer

If left unchecked, water hammer can lead to the following short- and long-term problems:

• Damage to appliances connected to the plumbing system
• Increased wear on plumbing fixtures, leading to more frequent replacements
• Leaks that can damage surrounding areas and lead to mold or mildew
• Weakened pipe joints may eventually fail and cause leaks

The Water Hammer Arrestor Solution

A water hammer arrestor is a simple yet effective installation designed to absorb the shock wave caused by sudden changes in water flow. It acts as a cushion, preventing the pipes from rattling and reducing the stress on your plumbing system.

How Water Hammer Arrestors Work

Water hammer arrestors contain a piston or diaphragm that separates a chamber of air from the water in your pipes. When water flow suddenly stops, the arrestor absorbs the resulting shock, preventing it from traveling through the pipes.

The device works by compressing the air chamber, which in turn slows down the water and dissipates the energy that would otherwise cause your pipes to bang.

Benefits of Installing a Water Hammer Arrestor

Installing a water hammer arrestor offers several advantages, including the following:

• Extends your plumbing system’s lifespan by reducing stress on pipes and joints
• Improves overall water flow and pressure consistency
• Protects plumbing fixtures and appliances from damage caused by water hammer
• Reduces noise from banging pipes, making your home more peaceful

Installing a Water Hammer Arrestor

While installing a water hammer arrestor requires some basic plumbing skills, it’s a project that many homeowners can tackle with the right tools and guidance. Here’s a step-by-step guide to help you through the process.

Tools and Materials Needed

Before you begin, gather the following tools and materials:

• Adjustable wrench
• Drill/driver
• Emery cloth
• Flux
• Lead-free solder
• Plastic pipe clips and screws
• Propane torch
• Screwdriver
• T-fittings
• Teflon tape
• Tubing cutter
• Water hammer arrestors for both hot and cold water lines

Preparing for Installation

Once you’ve gathered the necessary tools and materials, prepare for the installation process by following the steps below:

1. Locate the access panel near the problematic pipes to gain access to the plumbing system.
2. Turn off the water supply to the affected area to prevent leaks and water damage.
3. Open a couple of faucets on the lower level to drain water from the pipes, ensuring that the system is empty before you begin working.

Step-by-Step Installation Process

Ensure that you’ve fully drained the water from your pipes before beginning the installation process. Then, follow the steps below to install your new water hammer arrestor:

1. Unscrew and remove the access panel to expose the plumbing connections. This will provide a clear view of the pipes you’ll be working on.
2. Buff clean the hot and cold water supply pipes with a strip of emery cloth to ensure a good connection for the solder.
3. Hold a T-fitting against each supply pipe and accurately mark them for cutting.
4. Use a tubing cutter to remove sections from both the hot and cold water supply pipes at the marked locations.
5. Brush flux onto the fittings and pipe ends to prepare them for soldering.
6. Slip the T-fittings onto the pipes and solder them in place using a propane torch and lead-free solder. This will ensure a secure and leak-free connection.
7. Wrap Teflon tape around the threaded portion of each water hammer arrestor to ensure a tight seal.
8. Thread the arrestors into the T-fittings. Then, tighten the arrestors with an adjustable wrench.
9. Secure any loose water pipes to the wall framing with a plastic clip and a 1 5/8-inch screw to reduce potential movement and noise.
10. Reinstall the access panel and turn the water back on.
11. Test your work by opening the bathroom faucet all the way and then quickly shutting it off. Look out for any leaks or continued noise as you do this.

Maintenance and Troubleshooting a Water Hammer Arrestor

While water hammer arrestors are generally low-maintenance devices, we’ve shared a few maintenance tasks and outlined some potential issues below.

Regular Maintenance

To ensure your water hammer arrestors continue to function effectively, consider the following maintenance tips:

• Inspect visible pipes for signs of movement or vibration, securing them as needed to prevent noise and damage.
• Listen for any return of banging noises, which may indicate a problem with the arrestor or plumbing system.
• Periodically check for leaks around the arrestor and fittings and promptly address any issues.

Common Issues and Solutions

If you experience problems after installation, consider these potential solutions:

• Check the water pressure and consider installing a pressure-reducing valve if it’s too high, which can alleviate stress on the plumbing.
• Install additional arrestors if banging persists in other areas of the plumbing system, distributing the shock absorption.
• Tighten connections if you notice any leaks, ensuring all fittings are secure.

Alternative Solutions To Water Hammer Arrestors

While water hammer arrestors are highly effective, there are other methods to reduce pipe noise that you may consider, such as the following:

• Adjust water pressure, ensuring it is within a safe and consistent range.
• Install air chambers, but be aware they may become waterlogged and require maintenance over time.
• Replace old quick-closing valves with slow-closing models to reduce sudden stops in water flow.
• Secure loose pipes with additional strapping to prevent movement and vibration.

Our Conclusion

Installing a water hammer arrestor is an effective way to address noisy pipes and protect your plumbing system. With the right tools and some DIY know-how, you can solve this common household problem and enjoy a quiet, well-functioning plumbing system.