Skip to content

Solving Water Hammer: A Guide to Noisy Pipes

Water hammer is a common problem that many homeowners and building managers face. It is characterized by loud banging or knocking noises in the pipes when a faucet or valve is turned off. This phenomenon occurs when the flow of water is suddenly stopped or changed direction, causing a shockwave that reverberates through the plumbing system. Not only can water hammer be annoying, but it can also cause damage to pipes, fittings, and appliances over time. In this comprehensive guide, we will explore the causes of water hammer and provide practical solutions to help you solve this noisy pipe problem.

1. Understanding Water Hammer

Before we delve into the solutions, it’s important to have a clear understanding of what water hammer is and how it occurs. Water hammer is essentially a hydraulic shockwave that is created when the flow of water is abruptly stopped or changed direction. This shockwave travels through the pipes, causing them to vibrate and produce the characteristic banging or knocking noise.

Water hammer can occur in both residential and commercial plumbing systems, and it can affect both metal and plastic pipes. The severity of the noise and the potential damage caused by water hammer can vary depending on factors such as water pressure, pipe material, and the speed at which the water flow is stopped or changed.

2. Causes of Water Hammer

There are several common causes of water hammer, and understanding these causes can help you identify the source of the problem and implement the appropriate solution. Here are some of the main causes:

  • Rapid valve closure: When a valve is closed too quickly, it can create a sudden change in water flow, leading to water hammer. This often occurs when faucets or valves are forcefully shut off.
  • Water pressure fluctuations: If the water pressure in your plumbing system fluctuates significantly, it can contribute to water hammer. This can happen due to issues with the municipal water supply or problems with your home’s pressure regulating valve.
  • Improperly secured pipes: Loose or improperly secured pipes can vibrate more easily, amplifying the effects of water hammer. This is especially common in older plumbing systems where the pipes may have become loose over time.
  • Waterlogged air chambers: Air chambers are designed to absorb the shockwaves created by water hammer. However, if these chambers become waterlogged, they lose their effectiveness, allowing water hammer to occur.
  • Water velocity: High water velocity can increase the likelihood of water hammer. This can happen when the diameter of the pipe is too small for the volume of water flowing through it, causing the water to move at a higher speed.
See also  Troubleshooting Leaking Boat Plumbing: DIY Tips

3. Identifying Water Hammer

Before you can solve the problem of water hammer, it’s important to confirm that this is indeed the cause of the noise in your pipes. Here are some signs that can help you identify water hammer:

  • Loud banging or knocking noises: Water hammer is often characterized by loud noises that occur when a faucet or valve is turned off. These noises can be quite distinct and may sound like someone is hitting the pipes with a hammer.
  • Vibrating pipes: When water hammer occurs, the shockwave can cause the pipes to vibrate. You may be able to feel this vibration by touching the pipes while the noise is happening.
  • Visible pipe movement: In severe cases of water hammer, you may even be able to see the pipes physically moving or shaking when the noise occurs.
  • Damage to pipes or fittings: Over time, water hammer can cause damage to pipes, fittings, and appliances. Look for signs of leaks, cracks, or other damage that may be indicative of water hammer.

4. Solving Water Hammer

Now that you have a better understanding of water hammer and its causes, let’s explore some effective solutions to solve this noisy pipe problem:

4.1. Install Water Hammer Arrestors

Water hammer arrestors are devices that are designed to absorb the shockwaves created by water hammer. They consist of a sealed chamber with a compressible air cushion that absorbs the force of the shockwave, preventing it from causing the pipes to vibrate and produce noise. Installing water hammer arrestors at strategic points in your plumbing system can help alleviate the problem.

See also  How to Repair a Leaky HVAC Condensate Line

There are two main types of water hammer arrestors: piston-style and air chamber-style. Piston-style arrestors use a piston mechanism to absorb the shockwave, while air chamber-style arrestors rely on a column of air to provide cushioning. Both types can be effective, but it’s important to choose the right size and type of arrestor for your specific plumbing system.

4.2. Adjust Water Pressure

Fluctuations in water pressure can contribute to water hammer. If you notice that the noise occurs more frequently when the water pressure is high, it may be worth adjusting the pressure to see if it helps alleviate the problem. Most homes have a pressure regulating valve (PRV) that can be adjusted to control the water pressure. Consult a professional plumber to ensure that the pressure is adjusted safely and within the recommended range.

4.3. Secure Loose Pipes

If your pipes are loose or improperly secured, they can vibrate more easily and amplify the effects of water hammer. Inspect your plumbing system and identify any loose pipes or fittings. Use pipe hangers, brackets, or other appropriate methods to secure the pipes and reduce movement. This can help minimize the noise and prevent further damage to the pipes.

4.4. Drain Waterlogged Air Chambers

If your plumbing system has air chambers, it’s important to ensure that they are functioning properly. Over time, air chambers can become waterlogged, losing their ability to absorb the shockwaves created by water hammer. To drain a waterlogged air chamber, you will need to turn off the water supply to your home and open the faucets at the highest and lowest points in your plumbing system. This will allow the air chambers to refill with air and restore their effectiveness.

4.5. Reduce Water Velocity

High water velocity can increase the likelihood of water hammer. If you have a plumbing system with high water velocity, it may be necessary to reduce the speed at which the water flows through the pipes. This can be achieved by increasing the diameter of the pipes or installing flow restrictors or pressure-reducing valves. Consult a professional plumber to determine the best solution for your specific plumbing system.

5. Preventing Water Hammer

While solving water hammer is important, it’s also crucial to take preventive measures to minimize the occurrence of this problem in the future. Here are some preventive steps you can take:

  • Close valves slowly: When closing faucets or valves, do so slowly to avoid creating sudden changes in water flow.
  • Maintain stable water pressure: Regularly check and maintain the pressure regulating valve to ensure that the water pressure remains stable.
  • Secure pipes properly: During installation or renovation, make sure that all pipes and fittings are securely fastened to minimize movement and vibration.
  • Regularly inspect air chambers: Check the air chambers in your plumbing system periodically to ensure that they are not waterlogged. If necessary, drain and refill them to maintain their effectiveness.
  • Consider professional assistance: If you are experiencing persistent water hammer issues or if you are unsure about the best course of action, it’s always a good idea to consult a professional plumber. They can assess your plumbing system, identify any underlying issues, and recommend the most appropriate solutions.
See also  DIY Guide to Repairing a Leaky Foundation


Water hammer can be a frustrating and potentially damaging problem, but with the right knowledge and solutions, it can be effectively resolved. By understanding the causes of water hammer, identifying the signs, and implementing the appropriate solutions, you can eliminate the noisy pipes and protect your plumbing system from further damage. Remember to install water hammer arrestors, adjust water pressure, secure loose pipes, drain waterlogged air chambers, and reduce water velocity as necessary. Taking preventive measures can also help minimize the occurrence of water hammer in the future. If in doubt, always seek professional assistance to ensure the best outcome for your plumbing system.

Leave a Reply

Your email address will not be published. Required fields are marked *