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Plumbing systems are designed to transport water quietly and efficiently. Aside from the gentle sound of water flowing through the pipes, you shouldn’t hear much noise from your plumbing. However, if you start hearing banging, rattling, or vibrating noises, it’s a sign that something is wrong. These noises, often caused by a water hammer or hydraulic shock phenomenon, can occur in cold water and central heating systems. Understanding and addressing the cause promptly is essential to prevent damage to your pipework.
In this blog, we’ll explore the causes of these plumbing noises, the risks involved, and the steps you can take to stop the banging once and for all.
What Causes Banging Noises in Plumbing Pipes?
When your pipes make noise, it’s usually a sign of a pressure related problem. The most common cause of banging noises is hydraulic shock, a water hammer. This happens when a sudden surge of pressure occurs within the plumbing system.
A water hammer often happens when a tap or valve is suddenly closed, causing a quick change in water flow. The force of the water stopping abruptly creates vibrations in the pipes, which you hear as banging or pounding. This can happen in cold water pipes connected to your central heating system.
If the noise occurs when you open or close taps, don’t ignore it. It’s a sign that your plumbing system is under stress, and leaving it unresolved could lead to bigger issues.
How Hydraulic Shock (Water Hammer) Develops
Hydraulic shock occurs when the water flow is stopped or changed suddenly, creating a pressure surge within the plumbing system. This surge generates vibrations in the pipes, producing a banging noise commonly associated with water hammers.
There are a few key factors that contribute to the development of the water hammer:
- Sudden Changes in Water Pressure: When taps or valves are opened or closed too quickly, water is forced to stop or change direction instantly, creating a shockwave that travels through the pipework.
- Vacuum Formation: Sometimes, a water hammer occurs when a vacuum forms behind the water after a closed valve. If water flows quickly after the upstream valve has shut, the vacuum can cause pressure surges and vibrations.
- Faster Water Flow: The speed at which water moves through the pipes plays a significant role in the vibrations and pressure surges’ strength. Faster water flow means more intense vibrations, which lead to louder noises.
Why Taps and Valves Play a Key Role
Worn or faulty taps and valves are often the culprits behind hydraulic shock. Modern taps and valves aren’t designed to instantly stop or start the full water flow. Over time, wear and tear can affect their function, increasing pressure within the plumbing system.
Here’s how taps and valves contribute to the issue:
- Wear on the Valve Seats: As taps or valves age, the seating inside them can wear down or become loose, causing them to “jump” when water pressure increases. This results in sudden changes in water flow, triggering hydraulic shock.
- Increased Water Pressure: Worn or malfunctioning valves allow for quick changes in pressure, which causes banging noises. The problem might not always originate from the tap or valve closest to the noise. For example, a faulty tap in your kitchen downstairs could cause hydraulic shock in your bathroom upstairs.
Are Metal or Plastic Pipes More Prone to Noise?
The type of pipe material affects how much noise your plumbing system makes. Metal pipes like copper are more likely to transmit noise because they carry sound waves more effectively than plastic pipes.
- Metal Pipework: Due to their material properties, metal pipes tend to amplify the noise caused by water hammers, making the banging sound more obvious and alarming.
- Plastic Pipework: Plastic pipes can also experience hydraulic shock, but they tend to be quieter because plastic doesn’t transmit sound as effectively as metal. However, this doesn’t mean the underlying problem is less severe; it just means you may not hear it as clearly.
What Are the Dangers of Ignoring Noisy Pipes?
Ignoring banging noises in your plumbing system can lead to serious consequences. At the same time, the noise may seem like a minor inconvenience, but the vibrations caused by hydraulic shock can cause long-term damage to your pipes and fittings.
Here are some potential risks of leaving the water hammer unresolved:
- Stress on Pipes and Joints: The vibrations created by hydraulic shock place stress on the pipes, joints, and fixings. Over time, this stress weakens the pipework, making it more susceptible to leaks and damage.
- Pipe Rupture: In severe cases, the constant pressure surges and vibrations can cause the pipes to rupture. A ruptured pipe can result in significant water damage or even flooding inside your home, leading to expensive repairs.
- Increased Vibrations Over Time: If the banging noise has gotten louder or more frequent, it’s a sign that the issue is worsening. The more the vibrations increase, the higher the likelihood of a rupture or severe damage.
Steps to Stop Banging Noises in Plumbing Pipework
Fortunately, there are several steps you can take to address the issue of the water hammer and stop the banging noises:
- Call a Plumber or Heating Engineer: The first and most important step is to contact a qualified professional. They will be able to diagnose the cause of the problem and recommend the appropriate solution.
- Install Slow-Closing Valves: A common fix for water hammers is to install new taps or valves that close slowly. This helps to reduce the pressure surges that create vibrations in the pipework.
- Fit a Hydraulic Shock Arrestor: Installing a hydraulic shock arrestor is another effective solution. This device absorbs the pressure waves caused by the water hammer, preventing them from travelling through the plumbing system.
- Secure Loose Pipework: The banging noise can sometimes be caused by loose pipes moving when water flows through them. A plumber can check that the pipework is securely fixed to prevent movement.
How Combi Boilers Can Be Affected by Water Hammer
Interestingly, some combi boilers are more prone to water hammer than others. If your boiler seems affected by a water hammer, it could lead to additional problems, such as leaks.
- Cracks in the Manifold: In certain cases, the vibrations caused by the water hammer can create fine cracks within the boiler’s manifold. Over time, these cracks can lead to leaks, which must be addressed promptly.
If you suspect that your boiler is contributing to a water hammer in your plumbing system, it’s essential to have it inspected by a qualified heating engineer.
Conclusion
Noisy plumbing pipes can be more than just a nuisance; they could be a sign of hydraulic shock or water hammer, which, if left unaddressed, can cause significant damage to your plumbing system. By understanding the causes of these banging noises and taking steps to fix the issue, you can protect your pipework and avoid costly repairs.
If you hear banging, vibrating, or other unusual noises in your plumbing, don’t wait. Contact a professional plumber or heating engineer to inspect your system and make the necessary repairs.
Frequently Asked Questions (FAQs)
1. How do I stop the banging noise in my pipes?
You can reduce or eliminate the noise by installing slow-closing valves, fitting a hydraulic shock arrestor, or securing loose pipework. Consulting a plumber is the best way to identify and fix the root cause.
2. Can a water hammer cause my pipes to burst?
If left unresolved, the constant pressure surges and vibrations can weaken the pipes and joints, potentially causing them to rupture.
3. Why does my central heating make a banging noise?
This could be due to a water hammer, especially if the noise occurs when heating or water pipes expand and contract, causing pressure surges.
4. What is a water hammer arrestor, and how does it work?
A water hammer arrestor is a device that absorbs the pressure waves caused by hydraulic shock, preventing them from causing vibrations in your pipes.
5. Is water hammer more common in older homes?
Yes, older plumbing systems, especially those with worn-out taps, valves, or metal pipework, are more prone to water hammer.
