How to Effectively Stop Water Hammer in Your Pipes
Have you ever turned off a tap and heard a loud banging sound coming from your walls? That unsettling noise is more than just a nuisance, it’s called water hammer, and it could be a sign of underlying issues in your plumbing system.
If you’re wondering how to stop water hammer, this guide will walk you through what it is, why it happens, and how you can fix it, whether through DIY solutions or with the help of a professional plumber.
Key Takeaways
- Water hammer occurs when water flow is suddenly forced to stop or change direction.
- Left unresolved, it can lead to pipe damage, leaks, and costly repairs.
- Common solutions include draining the system, securing loose pipes, and reducing water pressure.
- Installing water hammer arrestors or upgrading valves may be required.
- Severe or recurring issues should be inspected by a licensed plumber.
What Is Water Hammer and Why Does It Happen
Water hammer, also known as hydraulic shock, is the result of a sudden change in water flow. It typically happens when a valve or tap is closed quickly, causing the moving water to slam against the shut-off point. This sends a pressure wave through the pipes, resulting in a loud bang or rattling noise.
Common causes of water hammer include:
- High water pressure
- Fast-closing taps or solenoid valves in appliances
- Loose or unsupported pipes
- Air chambers are becoming waterlogged
- Abrupt valve shut-off in dishwashers or washing machines
When functioning properly, plumbing systems absorb this pressure using air-filled chambers or flexible piping. But when those mechanisms fail or are missing, water hammer becomes both audible and problematic.
Dangers of Ignoring Water Hammer
It’s tempting to ignore a noisy pipe, especially if it only happens occasionally. However, untreated water hammer can lead to serious problems over time:
- Pipe damage: Repeated pressure surges can weaken joints and fittings.
- Leaks: Persistent hammering may loosen pipe connections and cause leaks behind walls or under floors.
- Appliance wear: Water heaters, washing machines, and dishwashers can suffer from pressure fluctuations.
- Structural impact: The vibrations may even cause cosmetic or structural damage in extreme cases.
Stopping water hammer early prevents minor annoyances from turning into expensive repairs.
DIY Fixes You Can Try
If your water hammer is mild or only occurs occasionally, you might be able to fix it yourself. Here are a few DIY solutions to get you started:
Drain the Plumbing System
Sometimes, restoring air cushions in your pipes is all it takes.
- Turn off the main water supply.
- Open all taps (hot and cold) in your house from the highest to the lowest point.
- Flush toilets and drain water completely from pipes.
- Once drained, turn the main water supply back on and close all taps slowly.
This helps reintroduce air into the system to absorb pressure.
Secure Loose Pipes
Banging may be due to pipes knocking against wall studs or flooring.
- Use pipe clips or foam insulation to secure loose sections.
- Focus on exposed pipes under sinks, behind access panels, or in basements.
Securing these areas can significantly reduce vibration and impact noise.
Inspect Shut-Off Valves
Fast-acting appliance valves can trigger water hammer.
- Check that valves near dishwashers and washing machines are fully open.
- Consider turning the tap slightly to reduce flow rate if hammering persists.
Making small adjustments to your fixtures can have a big effect on overall water flow stability.
Adjusting Water Pressure
High water pressure is a leading cause of water hammer. In many homes, the incoming pressure exceeds safe levels, causing turbulent flow and pressure surges when taps are closed.
How to check and reduce water pressure:
- Use a pressure gauge to test at a garden tap. Ideal home pressure should range between 350–500 kPa.
- If pressure exceeds this, consider installing a pressure-reducing valve (PRV).
PRVs are typically fitted at the mains connection and may require professional installation. They stabilise pressure across the whole property, reducing the risk of hammer and extending the life of appliances.
If you’re unsure of your water pressure or don’t have a gauge, a plumber can carry out a quick check and recommend the best course of action.
Installing Water Hammer Arrestors
When air chambers or pipe cushioning isn’t enough, water hammer arrestors are the next step.
What are they?
- Devices that absorb the shock wave of water hammer using a piston and sealed air chamber.
- Compact and highly effective, especially near appliances with fast-closing valves.
Where are they used?
- Behind washing machines, dishwashers, or under sinks.
- Installed inline with water supply hoses or directly onto fittings.
Some arrestors can be DIY-installed, but permanent, in-wall installations are best left to a plumber. They are especially recommended for modern homes with high-efficiency appliances.
Water hammer arrestors are a long-term fix that can be integrated during new installations or retrofitted into existing setups.
Upgrading Valves and Taps
Old, worn, or poorly designed taps and valves can contribute to water hammer, especially when they close too quickly or are used frequently.
Upgrade options:
- Slow-close taps: Gradually shut off water flow to prevent sudden pressure changes.
- Quarter-turn ball valves: Provide better control than older gate valves.
- Tap service or replacement: A plumber can service tap washers, cartridges, or recommend new hardware.
Newer valves and taps not only reduce the risk of water hammer, but they also improve the ease of use and reliability of your fixtures. In older homes, these upgrades can significantly reduce noise and improve the user experience.
Conclusion
Water hammer is a common plumbing issue, but it doesn’t have to be a permanent one. From adjusting water pressure to securing loose pipes and installing arrestors, there are multiple ways to quiet your noisy pipes and protect your plumbing system.
Still not sure how to stop water hammer in your home? Don’t ignore it. Even small knocks can signal bigger problems brewing behind your walls. The sooner you act, the less likely you’ll face serious repairs down the track.
Call DB Pro Plumbing for a Professional Fix
If your water hammer persists after trying DIY fixes, it’s time to call in the experts. At DB Pro Plumbing, we provide professional diagnostics and long-term solutions for noisy, damaged, or high-pressure plumbing systems across Sydney.
We can:
- Assess water pressure and pipe condition
- Install water hammer arrestors or PRVs
- Upgrade old valves and secure loose pipework
- Provide same-day service with no callout fee during business hours
Contact us to schedule an inspection or get expert advice on stopping water hammer for good.
