The 411 on a Water Hammer

April 16, 2026

Share this article

As a homeowner, you will most likely hear many different noises over time in your home. From creaking in the floors and moving air through your attic to the various sounds your appliances make, these noises are all common and extremely normal from time to time.
Unfortunately, a loud banging noise coming from your plumbing may be a cause for concern. Known as a water hammer, this loud bang is most common in older homes, but it can occur in new homes as well. Even though it affects many homeowners, most people are not familiar with the causes and treatment options for water hammers.
This guide and your 
plumber will help you address a water hammer in your own home.

Water Hammers

Firstly, you need to understand an actual hammer is not inside your water lines. The name refers to what sounds like a hammer banging on your pipes.
In reality, the noise actually stems from pressure in the pipes that occurs when water turns on or off suddenly. This pressure leads to the pipes moving and banging against the walls and other pipes.
You can compare a water hammer to a type of shock, which a variety of issues may cause.
A hydraulic shock is the most common type of water hammer. Caused by the sudden halt of water flowing, the hydraulic shock may occur when you turn off a faucet or close a water valve.
A water hammer may also stem from a thermal shock, which occurs when a sudden change in temperature occurs inside your pipes. This temperature change can increase the flow of water through your plumbing lines and cause the banging associated with the water hammer.
A clog within your plumbing lines may also cause the pipes to bang. Or if the pipes don't secure properly to your home's framing, the pipes will lack support to hold them in place when water moves through your plumbing lines. Both clogs and improper support can also cause the water hammer problem.

Professional Treatment

While the banging noise is annoying, a water hammer can also be very dangerous. If too much pressure builds up inside the pipes, the pipes may expand and crack, leading to water leaks and costly water damage.
An inspection by your plumber can help determine the cause of the water hammer issue before designing a plan to stop the noise while preventing future damage to your plumbing system and home.
In most cases, plumbers will drain the water lines first. Since clogs and excess air may cause a water hammer, flushing the pipes out may solve the problem.
Installing a surge arrester is also a common treatment for a water hammer. Arresters act as shock absorbers, reducing the amount of pressure inside the pipes, which prevent the water hammer. The arresters go directly into the water line and effectively absorb the shock in the pipes.
A pressure regulator may also be necessary if the water pressure in your pipes measures over 55 psi. Install the pressure regulator where the main water supply comes into the home. The regulator maintains the proper water pressure in your water lines, reducing the risk of a noisy water hammer and plumbing leaks.
Finally, if your water hammer stems from improperly secured pipes, your plumbing contractor can help. Pipe strapping can secure plumbing lines to your home's framing and reduce any possible movement while water runs through your pipes.
For assistance diagnosing and treating a water hammer or other plumbing problem, contact Moody Plumbing, Inc., today. We are happy to answer your questions and provide you with a free estimate.

Recent Posts

A wall-mounted gas water heater with control knobs, connected to metal piping, a pressure gauge, and power outlets.
April 16, 2026
Your hot water heater is an appliance that needs replacement at some point, with gas models lasting six to 12 years. Know that you are not forced to replace a hot water heater with the exact same kind that was there before, and that this is an opportunity to put in the hot water heater that you want. Here are some reasons why you should replace your hot water heater with a tankless model.
A gray electric water heater stands in a room beside an electrical panel, a blue toolbox, and a metal support bar.
April 16, 2026
Your water heater has always been there for you whenever you needed a nice, hot bath or to wash another load of laundry. However, you might have noticed lately that your water heater isn't performing as well as it did in the past, or maybe it's simply not meeting your family's needs. Here are four clear indications that it is time to either replace your current water heater or upgrade to a newer, more energy-efficient model.
Accessible restroom stall featuring a white toilet with grab bars on both sides and a small trash bin.
April 16, 2026
Did you know that each year roughly 235,000 individuals require emergency room visits due to bathroom-related injuries? Statistics show that nearly 14 percent of those visits require at least an overnight stay in the hospital. These types of injuries can happen while you take a bath or a shower, but they can also happen while you are on the toilet. As we age, our mobility, strength and agility all decrease. Therefore, it makes sense that there will be an increased risk of injury. Due to the fact that the bathroom is a cramped space and that there are wet surfaces, older adults are at increased risk of injury in the bathroom. Because of the increased risk, if you plan to try to maintain as much of your independence as possible as an aging adult, you need to make your bathroom as safe as possible. In order to do this, you need to consider upgrading the space. Below are some changes that can help you live at home as an aging yet independent adult.
A person in a beige shirt leans over a toilet in a bathroom, reaching inside the open tank to perform repairs.
April 16, 2026
Probably every homeowner at one time or another has encountered a situation wherein the toilet seems to run for no good reason. Sometimes, toilets even flush on their own, a problem commonly called "ghost flushing." Knowing why this happens and how you can stop this problem from occurring can help you take care of your home, conserve water and reduce your water bills.
Water flows from a shiny silver faucet into a marble bathroom sink next to toiletries and a stack of folded towels.
April 16, 2026
At first glance, all faucets seem to work the same way: turn a handle or two, and water flows forth. However, the inner workings of faucets vary greatly from model to model. There are actually four primary types of faucet valves - the areas inside faucets where hot and cold water are mixed and the flow rate is regulated. Each type of faucet valve functions in a different way to achieve the same purpose - the delivery of water at a desired rate and temperature. Below is more information about these valve types and what you should know about their operation and maintenance.
A person wearing gloves holds a bucket under a leaking bathroom sink while talking on a phone tucked between their shoulder.
April 16, 2026
Clogged drains are one of the most common problems that can affect your plumbing system, and they are also one of the most disruptive. A drain that no longer drains can cause all sorts of problems within your home, including water damage, burst pipes, and mold growth, all of which can be expensive and complicated to fix. Fortunately, there are a number of things that you can do to proactively reduce the risk of drains becoming clogged in the future, ensuring that worse issues don't manifest themselves.
Undersink plumbing with a silver chrome P-trap and two water supply valves mounted on a white tiled wall.
April 16, 2026
Backflow is of the hidden dangers of a plumbing system and poses a serious risk to human health. Backflow is possible in any environment, including industrial, commercial, and residential settings. It can even affect your home and its occupants. As a result, you should address potential backflow hazards and take measures to prevent them from causing harm. Below is more information about backflow, including why it occurs and how you can prevent it. What Is Backflow? When everything is working as it should in your home's plumbing system, water flows out of the supply line and into fixtures, through hoses, and in any other direction you choose. Normally, the water pressure on the supply side of your home is higher than the receiving side. In a backflow situation, however, water pressure is higher on the receiving side; this can happen for any number of reasons, including the loss of water supply due to a break in a city main or municipal pumping station failure. Why Is Backflow Bad? Backflow is dangerous because of the contamination threat posed to potable water systems. When backflow happens, water and contaminants enter the supply side of the system and are widely distributed. Contaminants can include a variety of potentially harmful substances, such as microorganisms, toxins, and airborne materials. When they flow freely through the potable water system inside your home, as a result of backflow, you can get exposure to disease or injury-causing substances by simply turning on the tap. How Is Backflow Prevented? There are several strategies in use to combat backflow and prevent it from occurring. The specific approach used depends on what type of device or fixture is affected and will be implemented by a plumbing professional. Here are the ways you can prevent backflow: Air Gap A simple means of preventing backflow is by implementing an air gap between the supply side and receiving side of a water line. The air gap breaks the vacuum that forms when a backflow situation occurs and keeps water from moving backward. Some fixtures in your home that rely on air gaps to prevent backflow include toilets, washing machines, and automatic dishwashers. Air gaps are effective, but they can fail if the air gap becomes flooded at any point. Atmospheric Vacuum Breaker An atmospheric vacuum breaker (AVB) is a backflow prevention device that works by introducing an air gap when you reduce the supply line pressure. If water pressure in the supply line falls, a special valve (poppet valve) opens automatically and air immediately enters the body of the valve. An AVB operates well in situations where a continuous air gap isn't desirable but provides an air gap when needed to prevent backflow. The main disadvantage of AVBs is their inability to keep airborne contaminants out of the water system. Check Valve A check valve is another type of backflow prevention device that operates by allowing water to flow in only a single direction. Any pressure from the other direction will cause the valve to close immediately. Check valves are enclosed inside the water supply line which makes them invulnerable to outside air contaminants. However, a single check valve can fail if jammed and may permit some contaminants to pass due to the time it takes for a closure to occur. That's why check valves are often paired to provide an extra measure of protection in the event of backflow. If you have any questions about backflow prevention, take a moment to contact Moody Plumbing, Inc. for assistance. Don't take chances that your home's occupants aren't sufficiently protected in the event of a backflow incident.
A technician in blue work overalls uses a screwdriver to repair an open gas water heater.
April 16, 2026
You can maximize the lifespan of your hot water heater by replacing the sacrificial anode. The purpose of the sacrificial anode is to corrode instead of your hot water heater. Most parts inside your home aren't designed to disappear as time goes on, but that's exactly what the sacrificial anode is supposed to do. The good news is replacing the sacrificial anode is an easy job for the average do-it-yourselfer. Below is a step-by-step procedure for removing the old part and replacing it with a new anode. 1. Turn Off the Hot Water Heater Before you begin removing the sacrificial anode, you will need to disconnect the electrical or gas supply to the hot water heater. Never attempt to work on a water heater that is in service, or you may find yourself with a nasty burn. First, turn off the hot water heater at its thermostat, then turn off the electrical power at the main circuit breaker panel, if the unit is powered by electricity. If your hot water heater is powered by natural gas, turn off the burner and pilot light at the thermostat, then turn the shut-off valve on the gas supply line to its 'off' position. Finally, turn off the cold water supply valve located at the top of the hot water heater. The cold water supply valve will usually be painted blue to differentiate it from the hot water outlet. 2. Drain the Hot Water Heater After the hot water heater has been completely disconnected, the next step is to drain the water inside the unit. This step will also provide the added benefit of removing sediment that has collected at the bottom of the tank. To drain the hot water heater, attach a garden hose to the drain valve located near the bottom of the unit. You only need to hand-tighten the connection. Once the hose has been connected, open the drain valve slowly to release the water from the tank. Be sure the opposite end of the hose is routed to a safe location such as a storm sewer or a five-gallon bucket. Do not empty the tank into your toilet or other drains, as the sediment may cause a clog. 3. Remove the Sacrificial Anode After the hot water heater has been drained, you are ready to remove the sacrificial anode. In most water heaters, the sacrificial anode is located at the top of the unit and looks like a large bolt head. Find a matching socket and use a ratchet to loosen the sacrificial anode from the hot water heater. Depending on how old the hot water heater is and how long the anode has been in place, you may need to apply a little muscle to loosen the part. Continue to unscrew and lift out the anode entirely from the hot water heater. You will probably notice the anode is pitted and may even partially be gone due to corrosion. 4. Install the New Anode Once you have removed the old sacrificial anode, briefly inspect the water heater threads to ensure they are relatively clean. You can use paper towels or even an old toothbrush to clean debris. Next, wrap the threads of the new anode with PTFE tape to create a watertight seal. Carefully lower the anode into the water heater and hand-tighten it, being careful not to cross-thread the anode and water heater threads. After the anode has been hand-tightened, use your socket and ratchet to tighten the connection. 5. Restore Service to the Hot Water Heater The last step in the process is to restore your hot water heater to service. Turn off the drain valve, disconnect the garden hose, and turn on the cold water supply valve at the top of the hot water heater. This will start filling the tank. After a few minutes, you can turn on the electricity or gas supply to the hot water heater. The final step is to turn on the hot water heater itself at the thermostat. If you have questions about hot water heaters, be sure to contact Moody Plumbing Inc. for help. They are ready to assist with any plumbing need you may have.​
A faucet pours murky, rust-colored water into a white bathroom sink, leaving brown stains around the drain.
April 16, 2026
Brown stains that remain on your plumbing components after the water from the faucets have dried are composed of various mineral and metal deposits. These contaminants are delivered into your home through your water supply lines. The deposits may originate in the local water supply itself or may leach into the water from deteriorating supply pipes. The cure for removing the contaminants will, therefore, differ according to the source of the problem. How Can You Determine the Source(s) of the Contamination? You must first discover the source of the problem before seeking a cure. This means that your water supply source must be tested and your plumbing evaluated in order to determine the necessary course of action. Your Water Supply The water that enters your home may be contaminated by mineral deposits before it reaches the supply lines. This is equally true whether a local municipality or a personal well supplies the water. Your water should be tested by a professional evaluation service to determine its mineral content if it is sourced from a private well. Water delivered by a local government agency will test the water at their facility, with results available to customers upon request. Your Plumbing Supply Pipes Contamination of your water supply through pipe deterioration is usually found only in older galvanized steel pipe. Although the galvanizing process adds a rust-inhibiting coating to the surfaces of the pipe, the inner surface faces a constant exposure to pressurized water. This exposure wears away the coating and begins to corrode the inner surface of the pipe. Corrosion begins to build along the inner surface of the pipes, narrowing the pipes' internal diameter. This creates additional pressure inside the pipes, which causes the accumulated corrosion to break away and enter the water supply. How Can Mineral Deposits Be Removed From Your Local Water Supply? Minerals such as magnesium and calcium are collected as your water supply source flows underground. This natural process becomes a problem in areas with rich deposits of these materials. Accumulations of calcium and magnesium will interfere with the internal machinations of plumbing components and produce staining and scale on the exterior surfaces of sinks, showers, and toilets. The primary method of removing these troublesome minerals is through the installation of a water softening system. Water Softening Systems These systems remove these minerals through the process of replacing calcium and magnesium ions with sodium ions through ion exchange. This is accomplished through bonding positively charged calcium and magnesium ions to negatively charged resin beads as the water enters a storage tank designed for this purpose. The tank then floods with salt water, which contains positively charged sodium ions. The overabundance of sodium ions overwhelms the normally superior positive charge of the calcium and magnesium ions, releasing and replacing them on the resin beads. The calcium and magnesium ions are then flushed out of the system, and the saltwater tank replenished. How Can Contamination by Deteriorating Steel Pipes Be Corrected? Replacement of older steel pipes is the only remedy for contamination of your water supply through corrosion. You can usually accomplish this through the installation of supply pipes composed of other materials that are more resistant to corrosion. Alternatives include copper, CPVC, and PEX pipe. Copper Copper pipe is the most expensive option, but also the most durable. It can last for decades before requiring replacement and is resistant to corrosion. Copper can survive house fires and physical trauma, unlike some less expensive options. CPVC CPVC (Chlorinated Polyvinyl Chloride) is a rigid plastic pipe. Immune to corrosion, it is much less costly and labor intensive than copper. Unlike copper, it is vulnerable to fire and physical trauma. PEX PEX pipe is a reinforced flexible type of plastic pipe. It shares many of the advantages of CPVC pipe, with an even greater ease of installation. It also shares the vulnerabilities of CPVC pipe. If you live in the Coral Springs, Florida area, and you're tired of stained shower walls and toilets, contact Moody Plumbing, Inc. We'll do whatever it takes to get your water to the pristine condition that you need and deserve.
A pile of light-colored, cylindrical wood pellets used for biomass fuel or animal bedding.
April 16, 2026
Most homeowners are surprised by how often they may be misusing their toilets. While the majority of flushing is necessary for removing human waste, the toilet is often used to dispose of items that can be dangerous to the entire plumbing and septic system. Improper disposal is one of the reasons toilets often clog, which is a common problem homeowners face. In fact, clogged toilets are so common, plungers are a staple in most households. These tools are usually effective for removing clogs quickly, but preventing the clogs in the first place is a smarter solution. Using this guide and your plumber's help , you will learn the dangers of flushing these common household items. 1. Flushable Wipes Whether used for removing makeup, cleansing yourself after using the bathroom, or wiping down toilets and countertops, flushable wipes should not actually be flushed. Even if they are labeled safe to flush, avoid placing them in your toilet because they will most likely cause a clog. While an excessive amount can lead to a clog, toilet paper is safe to flush because it breaks down faster, so there is less risk of serious plumbing and septic issues. The materials used in the pre-moistened cleansing and cleaning wipes are not the same as traditional toilet paper and they take longer to break down. Over time, these wipes will build up inside your toilet drain, increasing the risk of a clog. Eventually, the buildup will start affecting the septic lines, leading to a backed-up system that causes flooding and costly repairs. It is also important to note that these wipes contain harsh chemicals and bacteria that can harm the environment. After flushing these wipes, the chemicals and bacteria will move through your plumbing and septic system, affecting the sewer systems and local waterways. When possible, avoid using flushable wipes. If you must use them, then dispose of the wipes in your trash can instead of flushing them. 2. Cat Litter Cat litter is another common item that many people flush down their toilets. Even though this may seem like the easiest way to dispose of your cat's waste, cat litter is not capable of breaking down inside your plumbing and septic lines. In most cases, the litter is comprised of clay, which clumps together when it makes contact with water. The clumps of wet clay will sit inside your toilet drain and septic lines for extended periods of time without dissolving, causing severe clogs that can harm your toilet and septic tank. To clean up your cat's waste in a simple and safe manner, scoop the litter into a plastic bag and dispose of it in your trash can. 3. Prophylactics Prophylactics, or condoms, are another common item many people flush down their toilets because it seems like the most convenient option for disposal. Unfortunately, flushing condoms is also one of the most dangerous things you can do to your plumbing and septic system. The latex used to make condoms is designed to prevent bodily fluids from escaping, so the material is a lot stronger than you may think. Latex will not break down inside your toilet or while moving through the drains and plumbing lines. Constantly flushing condoms down your toilet will most likely cause a buildup of latex in your pipes and septic tank, which may lead to clogs and a failing septic system. The safest way to dispose of a condom is to wrap it in a few pieces of toilet paper before placing it into your trash bin. Proper understanding and ongoing maintenance will reduce the risk of clogs while prolonging the lifespan of your toilet and septic system. To learn more about your toilet and plumbing system, contact Moody Plumbing, Inc. today.​
Show More