How To Fix Hammering Water Pipes Fast

What causes hammering water pipes? Hammering water pipes, often referred to as water hammer, is typically caused by the sudden stopping or changing of water flow in your plumbing system. This abrupt halt creates a shockwave that travels through the pipes, making them vibrate and produce that distinctive banging or hammering sound. This phenomenon can also be caused by loose pipes, high water pressure, or air trapped in the system.

Can I fix hammering water pipes myself? Yes, in many cases, you can fix hammering water pipes yourself with a few simple tools and techniques. However, if you’re uncomfortable working with plumbing or if the problem persists, it’s always best to call a qualified plumber.

Who can I call if I can’t fix it myself? If you can’t fix hammering water pipes yourself, you should call a licensed plumber or a plumbing service company.

Deciphering the Bang: What Exactly is Water Hammer?

Water hammer is more than just an annoying noise; it’s a physical phenomenon that can, over time, cause damage to your plumbing system. When a faucet is turned off quickly, a valve is closed abruptly, or even when a washing machine or dishwasher completes its cycle, the momentum of the moving water has nowhere to go. This sudden stop creates a pressure surge, similar to a wave hitting a wall. This pressure wave travels back through the pipes, causing them to vibrate violently. This vibration is what we hear as the “hammering” or “banging” sound.

The causes of hammering pipes are varied but generally stem from the sudden interruption of water flow. Let’s break down the most common culprits:

Quickly Closed Valves: This is the most frequent cause. Think about turning off a tap with force, or even the solenoids in appliances like washing machines and dishwashers that shut off water supply very rapidly.
High Water Pressure: If your home’s water pressure is too high (generally above 80 PSI), even normal valve closures can create significant shockwaves.
Air in the System: Air trapped in the water lines can compress and expand unpredictably, leading to surges in pressure and subsequent hammering. This can happen after plumbing work or if your water supply has been interrupted.
Loose Pipes: Pipes that are not properly secured to walls or joists can vibrate more easily and amplify the sounds of water hammer.
Faulty Solenoid Valves: The valves within appliances like washing machines, dishwashers, and ice makers can sometimes fail or operate erratically, leading to sudden water flow changes.

Recognizing the Symptoms: Identifying Water Hammer

Before you can fix the problem, you need to be sure it’s indeed water hammer you’re dealing with. The primary symptom is that distinctive banging pipes sound. However, there are other indicators:

Sudden, Loud Noises: The sound typically occurs immediately after a faucet is turned off, a toilet is flushed, or an appliance like a washing machine stops filling.
Vibrations: You might feel a vibration in the pipes when the noise occurs.
Rattling or Thumping: The sound can vary from a sharp bang to a persistent rattle or thump.
Frequent Occurrences: If the noise happens every time you use a particular faucet or appliance, it’s a strong indicator of water hammer.

Simple Steps to Reduce Water Hammer Noise

Sometimes, the solution is as straightforward as adjusting your habits. Here are some easy ways to reduce water hammer noise:

Turn Off Faucets Gradually: Instead of slamming the tap shut, try to turn it off more gently. This gives the water a chance to slow down more gradually, reducing the shock.
Check Appliance Cycles: Pay attention to when the noise occurs with your washing machine or dishwasher. If it’s consistently at the same point in the cycle, it’s likely the appliance’s internal valves.

The Silent Pipes Solution: Installing a Water Hammer Arrestor

One of the most effective and permanent solutions for water hammer is the installation of a water hammer arrestor. These devices are designed to absorb the shockwave created by sudden water flow changes. Think of them as plumbing shock absorbers.

What is a Water Hammer Arrestor?

A water hammer arrestor typically consists of a sealed air chamber or a spring-loaded piston within a metal casing. When the shockwave occurs, the air or the piston compresses, absorbing the energy of the pressure surge and preventing it from traveling through the pipes.

Types of Water Hammer Arrestors:

There are two primary types of water hammer arrestors:

Air Chamber Arrestors: These are the older, more traditional type. They consist of a sealed chamber filled with air. When a pressure surge occurs, the water pushes into the chamber, compressing the air and dissipating the shock. Over time, the air can be absorbed into the water, reducing their effectiveness. They often require periodic “recharging” by draining the system.
Piston or Diaphragm Arrestors: These are more modern and generally more effective. They use a piston or a flexible diaphragm that is pushed by the surge of water, compressing a chamber of air or a spring. These are less prone to losing their charge and are often considered a more permanent silent pipes solution.

Water Hammer Arrestor Installation: A Step-by-Step Guide

Installing a water hammer arrestor is a manageable DIY project for many homeowners. However, if you are not comfortable with basic plumbing tasks, it’s best to hire a professional.

Before You Begin:

Gather Your Tools and Materials:
- Water hammer arrestor (choose one appropriate for your fixture – e.g., for a sink, washing machine)
- Adjustable wrench
- Pipe dope or Teflon tape
- Towel or bucket to catch residual water
- Safety glasses
Identify the Source of the Hammering: While you can install arrestors on multiple lines, it’s most effective to target the specific fixtures or appliances that are causing the problem. Common locations include:
- Under sinks (hot and cold water lines)
- Behind washing machines
- Near dishwashers

Installation Process:

Turn Off the Water Supply: Locate the main water shut-off valve for your house and turn it off completely. Alternatively, if you’re targeting a specific fixture like a sink, you can turn off the shut-off valves located behind the sink for both hot and cold water.
Relieve Water Pressure: Open the faucet or fixture furthest from the shut-off valve to drain any remaining water and relieve pressure in the pipes.
Disconnect the Supply Line: Using your adjustable wrench, carefully disconnect the flexible water supply line from the fixture (e.g., the valve under the sink). Have a towel or bucket ready to catch any dripping water.
Install the Water Hammer Arrestor:
- Apply pipe dope or Teflon tape to the threads of the arrestor’s inlet.
- Screw the water hammer arrestor onto the valve outlet. Hand-tighten first, then use the wrench to tighten it an additional quarter to half turn. Be careful not to overtighten, as this can damage the threads or the arrestor.
Reconnect the Supply Line: Reattach the flexible water supply line to the outlet of the newly installed water hammer arrestor. Tighten it securely with the wrench.
Turn Water Back On: Slowly turn the main water supply valve back on (or the individual fixture shut-off valves).
Check for Leaks: Inspect all connections for any signs of leakage.
Test the System: Turn on the faucet or appliance and then turn it off abruptly. Listen to see if the hammering sound has been eliminated or significantly reduced.

Important Considerations for Water Hammer Arrestor Installation:

Fixture-Specific Arrestors: Always use the correct type of arrestor for the specific application. Some are designed for direct connection to faucets, while others are intended for washing machine hookups.
Placement: For the best results, install the arrestor as close to the offending valve or appliance as possible.
Quantity: If multiple fixtures are causing water hammer, you may need to install arrestors on several lines.

Addressing Loose Pipes and Pipe Vibration Dampening

Sometimes, the hammering sound isn’t solely due to water pressure surges but is amplified by unanchored or loose pipes. This is where pipe vibration dampening comes in.

Securing Loose Pipes:

Inspect and Tighten: Visually inspect your exposed plumbing. Are any pipes visibly loose or rattling against walls or other surfaces?
Use Pipe Clamps and Straps: Purchase pipe clamps or straps from your local hardware store. These are designed to securely hold pipes in place.
Installation:
- Locate the loose section of pipe.
- Place a pipe clamp or strap around the pipe.
- Secure the clamp or strap to a sturdy surface (like a joist or wall stud) using appropriate screws or nails. Ensure the pipe is held firmly but not so tightly that it restricts water flow or causes stress.

Pipe Vibration Dampening Materials:

For areas where pipes might rub against surfaces or to further reduce the sound transmission, consider using dampening materials:

Foam Pipe Insulation: The foam sleeves used for insulating pipes can also act as a dampener. Wrap sections of pipe where you hear rattling or thumping against other surfaces.
Rubber Padding: Small pieces of rubber or specialized pipe vibration dampening pads can be placed between pipes and mounting surfaces.

Tackling Air in the Plumbing System

Air trapped in your pipes can be a significant contributor to water hammer. Here are some water hammer repair tips to address this:

How Air Gets into Your Pipes:

Plumbing Repairs: After any work that involves draining sections of your plumbing system, air can be introduced.
Municipal Water Supply Interruptions: If your local water supply is turned off for maintenance, air can enter the lines.
Well Systems: If you have a well, air can sometimes be drawn into the system if the pump runs dry or if there are leaks in the suction line.

Removing Trapped Air:

Flush Your System: The simplest way to remove air is to systematically flush your entire plumbing system.
Open Faucets Slowly: Starting with the lowest faucets in your home (e.g., basement sink, garden hose bib) and working your way up to the highest (e.g., upstairs bathroom sink), slowly open each faucet.
Let Water Run: Let each faucet run for a few minutes until all the sputtering and air is expelled and a steady stream of water flows.
Close Faucets: Once a steady stream is achieved, close the faucets in reverse order, starting from the highest and working your way down.
Check Appliances: Don’t forget to run water through your washing machine or dishwasher to ensure air is cleared from those lines as well.

Investigating High Water Pressure

Excessively high water pressure is a common culprit for aggressive water hammer. The ideal residential water pressure is typically between 40 and 60 PSI. Anything above 80 PSI is considered too high and can stress your plumbing system.

Checking Your Water Pressure:

Water Pressure Gauge: You can purchase an inexpensive water pressure gauge that screws onto an outdoor hose bib or laundry faucet.
Procedure:
1. Ensure no water is being used in the house.
2. Attach the gauge to a hose bib.
3. Open the hose bib fully.
4. Read the pressure displayed on the gauge.

Reducing High Water Pressure:

Pressure Reducing Valve (PRV): If your water pressure is consistently too high, the solution is to install or adjust a Pressure Reducing Valve (PRV).
- Location: The PRV is usually located where the main water line enters your house, often near the main shut-off valve.
- Adjustment: Some PRVs have an adjustment screw. Turning this screw can raise or lower the pressure.
- Replacement: If your PRV is old, malfunctioning, or non-adjustable, it may need to be replaced. This is a job best left to a professional plumber.

When to Call a Professional Plumber

While many water hammer issues can be resolved with DIY methods, there are instances when professional help is essential:

Persistent Hammering: If you’ve tried the above steps and the hammering continues or worsens, it’s time to call a plumber.
Uncertainty About Causes: If you’re unsure about the source of the noise or how to proceed, a professional can diagnose the problem accurately.
High Water Pressure Issues: Adjusting or replacing a PRV requires specific knowledge and tools. Incorrect adjustments can lead to pressure problems elsewhere in your system.
Complex Plumbing Systems: Older homes or homes with complex plumbing configurations might require a plumber’s expertise.
Damage Concerns: If you suspect the water hammer has already caused damage to your pipes or fixtures, a plumber can assess and repair it.

Maintaining Your Pipe System for Longevity

Regular pipe system maintenance can prevent many plumbing issues, including water hammer. Here are some tips:

Periodic Pressure Checks: Check your home’s water pressure at least once a year.
Inspect for Leaks: Regularly check for any signs of leaks around pipes and fixtures.
Listen to Your Pipes: Pay attention to any unusual noises your plumbing system makes.
Address Minor Issues Promptly: Don’t let small noises or drips turn into bigger problems.

Frequently Asked Questions (FAQ)

Q1: How much does it cost to install a water hammer arrestor?
A1: The cost of a water hammer arrestor itself is typically between $10 and $30. If you hire a plumber for installation, expect to pay anywhere from $100 to $300 per arrestor, depending on labor rates and the complexity of the installation.

Q2: Will a water hammer arrestor make my pipes completely silent?
A2: A water hammer arrestor is highly effective at eliminating the loud banging noises associated with water hammer. While it significantly reduces or eliminates the “hammering” sound, some minor vibrations or sounds might still be present depending on the overall condition of your plumbing system and the severity of the original problem. It is an excellent silent pipes solution for the primary issue.

Q3: Can water hammer damage my plumbing?
A3: Yes, persistent water hammer can cause significant damage over time. It can loosen pipe supports, lead to leaks at pipe joints, damage valve seals, and even crack pipes or fixtures due to the repeated stress and shockwaves.

Q4: How often do I need to replace a water hammer arrestor?
A4: Modern piston or diaphragm arrestors are designed to last for many years and often do not require replacement unless they fail. Older air chamber types may lose their effectiveness over time and might need to be recharged or replaced.

Q5: What are the warning signs of water hammer besides the noise?
A5: Besides the banging sound, you might notice your pipes vibrating, a rattling sound when water is running, or that faucets and appliances seem to be “shuddering” when they operate.

By following these detailed steps and water hammer repair tips, you can effectively tackle that annoying hammering in your pipes and enjoy a quieter, more reliable plumbing system. Remember, for any persistent or complex plumbing issues, a qualified plumber is your best resource.