Water hammer is a phenomenon that can occur in household plumbing systems when water flow is suddenly stopped, causing a shockwave and loud banging noises in the pipes. While it may seem like just an annoyance, water hammer can actually cause serious damage over time if not addressed:
- The repeated shockwaves and vibrations can weaken pipe joints and cause leaks
- The excessive force can damage connections, valves, and appliances
- In extreme cases, water hammers can even cause pipes to rupture.
Installing water hammer arresters on both the hot and cold water supply lines can help mitigate these issues.
As a homeowner, it’s important to understand what causes water hammer and how to prevent or fix it to avoid costly plumbing repairs. In this article, we’ll cover everything you need to know.
What You Need to Know About Water Hammers
Definition of a Water Hammer
Water hammer, also known as hydraulic shock, is a common plumbing issue that occurs when there is a sudden change in water flow. This shockwave bangs against the pipes and can result in a loud banging noise, which can be loud enough to shake the house and damage pipe connections and joints.
Imagine turning off a faucet quickly and hearing a loud thud—this is a water hammer in action. The abrupt halt in water flow creates a pressure surge, sending shockwaves through the plumbing system.
Explanation of Hydraulic Shock
Hydraulic shock is the technical term for the phenomenon behind the water hammer. When water, or any fluid, is suddenly stopped or its direction is changed abruptly, it creates a shockwave that travels through the pipe.
This shockwave can cause the pipes to vibrate and produce the characteristic banging noise associated with a water hammer. The force of these shockwaves can be surprisingly strong, leading to potential damage over time. Understanding hydraulic shock helps grasp why water hammer occurs and why it’s crucial to address it promptly.
Importance of Addressing Water Hammer
Addressing water hammer is essential for maintaining a healthy plumbing system. Ignoring it can lead to significant damage, including cracked pipes, loose connections, and damaged valves.
Over time, these issues can escalate, resulting in costly repairs, water leaks, and even safety hazards like flooding. By understanding the causes of water hammer and taking preventive measures, homeowners can protect their plumbing system and avoid expensive repairs. Regular maintenance and timely interventions ensure a safe and efficient plumbing system.
Common Causes of Water Hammer
There are a few main culprits that tend to cause water hammer in residential plumbing:
- Quick-closing valves on dishwashers, washing machines, and faucets
- Loose pipes that aren’t properly secured and vibrate when the flow stops
- High water pressure above 60 psi
- Waterlogged or non-existent air chambers meant to cushion shockwaves
- Modern mixer taps that allow for instant shut-off of water flow.
Knowing the causes can help prevent water hammer or troubleshoot the source if you’re already experiencing it.
Effects of Water Hammer
Damage to Pipes and Plumbing Fixtures
Water hammer can cause significant damage to pipes and plumbing fixtures, including:
- Cracked or Broken Pipes: Repeated shockwaves can weaken the structural integrity of pipes, leading to cracks or even complete breaks.
- Loose or Damaged Pipe Connections: Water hammer vibrations can loosen pipe connections, causing leaks and reducing the plumbing system’s efficiency.
- Damaged or Worn-Out Valves and Fittings: The excessive force from the water hammer can wear out valves and fittings, leading to malfunctions and the need for replacements.
- Water Leaks and Flooding: A persistent water hammer can create leaks, which, if left unchecked, can result in significant water damage and flooding.
- Increased Risk of Pipe Corrosion and Scaling: The constant stress on pipes can accelerate corrosion and scaling, further compromising the plumbing system.
By addressing and preventing water hammers, homeowners can protect their plumbing systems and prevent costly repairs. Regular maintenance, such as checking for loose pipes and worn-out valves, can also help avoid water hammers and ensure a safe and efficient plumbing system.
Implementing solutions like installing water hammer arrestors or pressure regulators can provide long-term protection against the damaging effects of water hammers.
How to Prevent Water Hammer
Secure Your Pipes
Ensure all accessible water supply pipes, especially in the basement or crawlspace, are securely fastened with pipe clamps or straps so they can’t move and bang against surfaces. Use foam insulation around pipes to further dampen vibration.
Install a Water Pressure Regulator
If your home’s water pressure is above 60 psi, consider having a plumber install a water pressure regulator (PRV) where the main water line enters your house. This will keep the pressure safe and reduce the force of shockwaves.
Avoid Quick-Closing Fixtures
When replacing faucets, toilets, dishwashers, and washing machines, look for models with slow-closing valves that don’t abruptly cut off the water flow. If you have existing quick-closing valves, see if you can adjust them to close more gradually.
Maintain Air Chambers and Water Hammer Arrestors
Air chambers are vertical pipe segments near valves and faucets that provide air cushion to absorb shockwaves. Over time, these air chambers can become waterlogged and stop working.
To recharge them:
- Turn off the main water supply
- Open the highest faucet in your home to drain the system
- Turn on the lowest faucet until the water stops flowing
- Turn the main water supply back on
Repeat this every few months to keep air chambers functional. If your plumbing doesn’t have air chambers, consider having a plumber retrofit them. Alternatively, installing water hammer arresters can provide a more permanent solution without regular maintenance.
How to Fix Existing Water Hammer
If you’re already dealing with water hammer, here’s how to fix water hammer effectively. First, try the air chamber recharging procedure above. This alone often solves the issue.
If that doesn’t work, here are some other solutions to try, in order of increasing cost and complexity:
- Secure loose pipes: Identify any vibrating pipes and secure them tightly with clamps or straps.
- Install water hammer arrestors: These sealed air chambers screw onto the offending pipes near valves and absorb shock waves without needing recharging. Prices for a water hammer arrestor range from $15-50 each. Exploring various water hammer solutions can help you find the most effective method for your specific situation.
- Replace problem valves: If the water hammer originates from a specific quick-closing valve that can’t be adjusted, replace it with a slow-closing model. Costs will vary based on the valve type.
- Call a plumber: For severe water hammer issues, hire a licensed plumber to inspect your entire system, identify the root causes, and implement solutions like pressure regulation, air chambers, pipe fastening, or rerouting.
Key Takeaways
- Water hammer is a common plumbing issue caused by shockwaves from abrupt changes in water flow.
- Possible causes include quick-closing valves, loose pipes, high water pressure, and waterlogged air chambers.
- Water hammer can lead to leaks, damage, and even pipe ruptures over time
- Homeowners can prevent water hammer by securing pipes, installing pressure regulators and slow-closing valves, and maintaining air chambers or installing water hammer arresters
- Existing water hammer can be fixed by recharging air chambers, installing water hammer arrestors, replacing problem valves, or hiring a plumber for more complex solutions
- Costs to fix a water hammer can range from $0 to over $1,000, depending on the required repairs.
Contact Woden Valley Gasfitting & Plumbing for a tailored quote on any issues you may be experiencing with a water hammer.
Water Hammer FAQs
How do I know if I have a water hammer?
The most obvious sign is a loud banging sound coming from your pipes when water is turned off abruptly, like when a faucet is closed, or the washing machine stops filling. You may also notice your pipes shaking or vibrating.
Is water hammer dangerous?
While the water hammer itself isn’t directly dangerous to people, it can cause damage to your plumbing system over time. Leaky pipes from water hammers can also create slip hazards or lead to water damage and mould growth if not fixed.
Can a water hammer increase my water bill?
No, a water hammer does not waste or increase your water usage. However, leaks caused by water hammer damage can waste water and drive up your bill if left unrepaired.
How much does it cost to fix a water hammer?
The cost depends on the severity of the issue and the water hammer solutions needed. Minor water hammers can often be resolved for free by homeowners by securing pipes or recharging air chambers. More complex cases requiring professional help and parts like water hammer arrestors or pressure regulators can cost anywhere from $200 to over $1,000.
