Are you experiencing issues with the pipes in your home making a loud banging or clanging noise when you turn off the water? Banging pipes is a fairly common plumbing issue and not something you should ignore. The issue is known as a water hammer.
What Is Water Hammer?
Water hammer is the term used to refer to a hydraulic shock inside of a pipe. It is essentially when there is a sudden surge of pressure inside the pipe that occurs when the water moving through it suddenly stops or has to change direction.
Water hammers typically occur when you turn off your shower, faucet, or other plumbing fixtures. Your plumbing may also experience multiple water hammers when your washing machine or dishwasher is running since these units turn the water on and off multiple times throughout a cycle.
The reason this issue is called a water hammer is that the shockwave causes the pipe to move and knock against wall studs, floor joists, or the inside of a cabinet, which produces a loud banging sound. If your pipes are not supported properly, they will move even more and produce an even louder banging sound.
Hearing your pipes banging can obviously be annoying. However, the bigger issue is that your pipes could easily get damaged and start leaking if they keep banging this way. If left unchecked, a water hammer could eventually lead to major water damage or cause mold to start growing inside your wall or ceiling.
Water Hammer Causes
Water hammers occur simply because the pressure in your plumbing system is fairly high. When you turn off your faucet or shower, the valve inside it instantly closes. This blocks off the flow of water, and the high-pressure results in the water flowing through the pipe suddenly changing direction and causing the pipe to move or shift.
However, high water pressure generally isn’t the reason that you hear a water hammer unless your pressure is much too high. Instead, water hammers normally happen for one of the following reasons.
Loose Pipes
The most common reason you’ll hear frequent water hammers is that some of the hot or cold water pipes in your home are loose and not properly secured or supported. If you only hear the water hammer when you shut off a particular sink or shower, it’s usually a sign that either the hot or cold supply line running to that fixture is loose.
All of the pipes in your home should be secured to the wall studs or floor joists with pipe straps or hangers to ensure that they are properly supported. If one of your pipes is loose and producing a water hammer, you’ll need to have a plumber add additional straps or hangers or tighten the existing ones.
This will often require cutting a hole in the wall or ceiling to access the entire length of the pipe. While this can be annoying, it will likely be necessary at some point anyway. If you don’t get the pipe properly secured, the water hammer will typically cause the pipe to start leaking.
Worn-Out Stop Valve
The shut-off valve on the water line to your toilets and sinks is known as a stop valve. If the washer in a stop valve is worn or the gland packing is loose, it can also lead to a water hammer whenever water stops flowing. In this situation, the shockwave that results when the water suddenly stops can bang against the valve handle or jumper and produce a loud noise.
Any time you’re experiencing issues with frequent water hammers, a plumber will check all of the stop valves to make sure that they’re in good condition and not worn. While it is possible to replace a worn washer or tighten a loose gland packing, the better option is generally to just replace the entire stop valve.
Trapped Air Inside Your Pipes or Clogged Air Chambers
Air normally shouldn’t get inside your pipes since they are constantly full of water. However, air can, sometimes, get in due to issues with the municipal water supply system. Trapped air inside a pipe can essentially create a vacuum that suddenly stops water from flowing, which will again produce a shockwave that rattles your pipes.
If you suddenly notice a water hammer and you’ve never had any issues before, it most likely means that there is air trapped in your plumbing. In this case, you may need to have a plumber install air-relief valves at various points in your plumbing system to avoid future water hammer issues.
Many homes also have air chambers on some of the pipes that are specifically designed to prevent water hammers. Whenever there is a sudden shockwave or surge in the pipe, the air in the chamber instantly compresses and absorbs the shockwave to prevent a water hammer from occurring.
Air chambers can sometimes become clogged with mineral deposits and stop working. If the chamber is clogged, the air inside it won’t be able to absorb the shockwave, and you’ll start hearing frequent water hammers. In this situation, you’ll need to have a plumber check the air chambers and replace any that are clogged.
Solenoid Valve in Dishwasher or Washing Machine
Most newer dishwashers and washing machines have electronically controlled solenoid valves that instantly open and close. If you’ve recently installed a new washing machine or dishwasher and suddenly start hearing water hammers when it runs, the problem is almost certainly due to the solenoid valve. Solenoid valves close so quickly that they will often cause a water hammer, and the problem will typically get worse as the valve starts to wear out.
If you have a solenoid valve in an appliance that is causing frequent water hammers, it usually means that you need to replace the water supply line to the unit. If the supply line is a copper pipe, it will almost always end up shutting and banging any time the solenoid valve closes. In this case, the solution is usually to replace the copper pipe with a flexible hose or a plastic PEX pipe. Although a hose or PEX pipe will still shudder due to the shockwave produced when the solenoid valve instantly closes, it won’t bang and produce a water hammer sound.
If you’re experiencing issues with water hammers in your home, our crew at Norman Air is here to help. We can inspect your plumbing to determine what is causing the water hammer and how best to fix the problem.
Our team of expert plumbers has years of experience repairing all types of plumbing, drain, and sewer issues, and we also specialize in plumbing installation and gas line services. In addition, we employ a team of certified HVAC technicians who can help with your heating and air conditioning repair, installation, and maintenance needs, and we offer a full line of professional electrical services.
Our company serves customers in Norman and throughout the Oklahoma City Metro area, so give us a call today for help overcoming your water hammer issues or if you need any other home service.
