A loud bang from your walls after turning off the faucet can be startling. This alarming sound points to a common plumbing problem that many homeowners face. The noise happens when water flow stops suddenly, creating what experts call water hammer. The problem goes beyond being just annoying – it can damage your plumbing.
Noisy pipes after shutting off water should raise red flags. The force on valves can spike pressure to ten times above normal working levels. Hot water pipes make these sounds more often than cold ones because they expand and contract more. The knocking sounds you hear when your washing machine or dishwasher stops likely come from water hammer.
The ideal water pressure in your home should stay between 60 to 80 pounds per square inch (psi). Pressure above this range can create loud bangs throughout your plumbing system, especially if pipes aren’t secured properly. The good news is that you can fix most pipe noise problems without major repairs.
In this piece, you’ll find out why these startling noises happen and learn quick, effective ways to stop your water pipes from banging.
What causes banging or knocking in pipes?
Those mysterious bangs, knocks, or thumps from your plumbing system can be traced back to a few common problems. You can fix these issues before they get worse by learning what causes them.
When do the noises usually happen?
Your pipes make these noises in specific situations:
- During hot water use anywhere in your home
- Right after shutting off hot or cold water
- When using cold water
- Random times during morning or evening hours
These sounds also pop up when appliances like washing machines and dishwashers stop using water. Your modern appliances use solenoid-triggered valves that snap shut quickly, unlike regular faucets that close more slowly.
Why do pipes knock when water is turned off?
A phenomenon called water hammer or hydraulic shock causes most pipe knocking. The pipes shake when flowing water stops suddenly and creates a pressure shockwave that travels through your plumbing. The water’s movement energy has nowhere to go when valves shut quickly, which makes pipes shake and bang against nearby structures.
Water hammer sounds like one loud bang, several bangs, or shuddering noises. Your pipes will vibrate more violently when water flows faster through them.
Other causes include loose pipes without proper support, high water pressure above the safe range of 40-80 PSI, and thermal expansion as hot water pipes expand and contract with temperature changes.
Are noisy water pipes dangerous?
Noisy pipes might seem just annoying at first, but untreated water hammer can damage your plumbing system. Constant pressure spikes and vibrations put stress on your pipework, joints, and fixings. Hydraulic shock can make pipes burst in severe cases and cause flooding or water damage in your home.
Louder banging noises over time mean the vibrations have gotten stronger, which increases the risk of pipe damage. High water pressure needs immediate attention because it can damage your appliances over time.
Contact Western Rooter today to get a free estimate!
Common reasons your pipes are making noise
Those mysterious pipe noises can tell you a lot about what’s wrong with your plumbing. Here are four common reasons why your pipes make singing, banging, and knocking sounds.
Loose or unsupported pipes
Plumbers secure pipes to wall studs or framing with straps or brackets during installation. The vibration from rushing water can loosen these attachment points. Water passing through pipes with extra space creates a swaying motion that guides them to bang or rattle.
A gentle push on visible pipes will show if they’re loose. Your pipes need straps or clips every 12-16 inches and at each direction change for proper support. You’ll find this issue mostly in cellars and airing cupboards.
High water pressure
Your plumbing system faces serious strain from excessive water pressure. Most homes work best with pressure between 40-80 PSI. Pressure above this range sends water through pipes too fast and this is a big deal as it means that vibrations create humming or banging sounds.
High pressure doesn’t just make noise – it shortens your appliances’ life. Your pipe joints could break and pipes might burst. A pressure gage on an outdoor faucet will help you figure out if pressure is your issue.
Sediment buildup in water heater
Your water heater’s knocking or rumbling usually points to mineral sediment accumulation. Calcium and lime settle at the tank’s bottom and trap water where the gas burner sits.
The burner heats this trapped water until it bursts through the sediment layer with a popping sound. While your heater won’t explode, tank overheating can get pricey if leaks or bursts cause water damage.
Ever-changing valves in appliances
Washing machines and dishwashers use solenoid valves that shut almost instantly. These quick-closing valves send shockwaves through your plumbing system and create that familiar banging.
The banging gets worse as valves age. Your pipes shudder from sudden water stoppage, which can damage connections throughout the system.
Contact Western Rooter today to get a free estimate!
How to fix banging water pipes fast
You can fix those annoying banging pipes without professional help. These four proven solutions work well before you need to call a plumber.
Secure loose pipes with clips or straps
A gentle push on visible plumbing reveals if pipes move. Wobbly pipes need extra support right away. The loose sections need plastic or metal straps every foot and at each direction change. Your copper pipes work well with either copper or plastic straps, while plastic pipes need plastic fasteners to avoid corrosion.
Flush your water heater to remove sediment
Your water heater’s distinctive knocking sounds come from sediment buildup at the bottom. This buildup makes your heater less efficient and reduces its lifespan. The flushing process works like this:
- Switch off the heater and cold water supply
- Add a drain hose and let air enter the system
- Check the water after opening the drain valve
- Keep flushing in bursts until clear water flows
Install a water pressure regulator
Your home’s water pressure should stay between 40-60 PSI. High pressure beyond this range damages pipes, so a regulator becomes essential. The installation needs you to find the main water line, cut off the supply, and place the regulator after the main shutoff valve.
Replace or adjust solenoid valves
Appliances with faulty solenoid valves make loud bangs during closure. The adjustment requires a simple turn of the valve’s adjustment screw. Replacement works by turning the solenoid counterclockwise, disconnecting wires, putting in the new one, and reconnecting.
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What to do if it’s water hammer
Banging sounds in your pipes? Water hammer is the most likely culprit. Let’s learn about solutions that can solve this noisy problem.
What is water hammer and how it works
Your pipes make these sounds when flowing water stops suddenly. This creates a pressure wave that moves backward through the pipes. Quick-closing valves trap water that has nowhere to go. The pressure spike this is a big deal as it means that normal working pressure by ten times, which makes pipes bang against walls or joists.
How to stop pipes from knocking using arrestors
Your plumbing system needs shock absorbers called water hammer arrestors. These devices work like cushions with an air or spring chamber that squeezes when pressure spikes happen. The shockwave gets absorbed before it creates noise or damage. Modern homes should have arrestors installed close to washing machines, dishwashers, and quick-closing valves.
Installing a water hammer arrestor step-by-step
Start by turning off your water supply. Find the pipe section near the noisy appliance. You can attach the arrestor directly to the valve or use a short pipe nipple. Secure all connections with pipe tape to stop leaks. The final step is to restore water flow slowly and test the system by running and stopping water quickly.
When to call a plumber for help
You should get professional help if the banging continues after installing arrestors. The same applies if you cannot find problem areas or have pipes hidden in walls. Ongoing water hammer can damage pipe joints and connections over time.
Call Western Rooter now to get your free estimate!
Conclusion
Banging pipes definitely cause more than just annoying noise in your home. This piece explains how water hammer is the most common culprit, while loose pipes, sediment buildup, and high water pressure also contribute substantially to these unsettling sounds.
Quick action prevents what could happen to your whole plumbing system. Your pipes can develop weakened joints, leaks, and maybe even burst, flooding your home if you leave the banging untreated.
You can try several DIY solutions for this common problem. Simple fixes like securing loose pipes with straps, flushing your water heater regularly, adjusting water pressure, or installing water hammer arrestors solve the issue without getting pricey. These steps often eliminate those startling sounds and extend your plumbing system’s lifespan.
The pipes might have more complex problems if these solutions don’t work. Pipes hidden behind walls or under floors create challenges that professionals handle best. The persistent water hammer despite your efforts signals the need for expert help.
Your home’s plumbing needs proper care just like any other major system. Early attention to strange noises saves you from expensive repairs later. Those random bangs and knocks warn you that your pipes need attention before small problems turn into major emergencies.
Contact Western Rooter today for a free estimate!
