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Why Are Groaning Pipes Making Noise When the Water Is Turned Off?

There can be several different underlying causes for noises coming from the water pipes within your home. It is important to determine what type of sound the pipes are making to better diagnose and troubleshoot the problem.

Water pipes that make a groaning or hissing noise often indicate a constriction somewhere in the waterline. As the water flows through the narrower section, it creates this noise. This problem commonly develops in faucets and toilets as washers and internal fixtures wear out.

To determine the source of the problem, you will want to check both the hot and cold water lines. Start by turning on just the cold water. Then shut off the cold water and turn on just the hot. If the sound is evident with either just the hot or cold water on or is persistent with both water lines, the faucet needs to be replaced.

TIP: If you notice the groaning noise occurs in all the faucets of your home, chances are there is a restriction somewhere in the plumbing lines.

moaning sounds plumbing

Why Do Pipes Make Groaning, Whining, and Moaning Sounds?

While there’s some humor in pipes making moaning sounds, water pipes groaning when the water is turned off or on is a nuisance. Unfortunately, it’s really no laughing matter. When pipes make these funny noises, it means there’s a problem. 

Luckily, plumbers are fluent in every language that your pipes speak. Usually, it’s easy to find a source to correct.

Why Does Plumbing Make Noise? Common Causes of Groaning Pipes

Here are some common examples of causes behind groaning pipes. 

  • High water pressure: Loud horn-like sounds indicate that there’s too much pressure on the pipes. It’s not always a problem, but it has the potential to cause pipe damage, leaks, and wasted water.
  • Faulty toilet fill valve: There’s a distinct moan that comes from bathroom pipes when the toilet fill valve doesn’t work. Cut off the water to the toilets one by one to find the problem and replace the fill valve assembly. 
  • Air in the pipes: Whining and moaning sounds when you turn on a faucet point to air caught in the pipes. This indicates a problem with the bleed-off system. It’s best to work with a professional plumber to resolve this. 
  • Blockages: A blocked pipe can quickly become a burst pipe if you don’t address it properly. If the groaning pipes accompany a backed-up toilet, foul smell, or slow drain, call a plumber ASAP.

Types of Sounds & Sources

With toilet hissing sounds, the flapper and/or ballcock valve could be worn out and need to be replaced. Remove the back toilet cover, flush the toilet, and watch how the tank refills. If it continues to fill with water past the desired shutoff and runs down the overflow, this, too, could create a hissing sound.

Another type of noise your pipes can make is a pounding or banging sound. This noise occurs when the force of the water flowing through the pipes is abruptly stopped. For instance, as your washing machine is filling with water, you may notice this type of sound when it stops filling.

You may also notice this sound if the pipes inside your walls are not secured in place. As the water flows through the pipes, it can cause movement and a “banging” against the interior wall. To remedy loose pipes, have your plumber secure them in place using different methods.

For more persistent banging noises, there are special “shock-absorbing” devices you can be incorporate into your home’s plumbing. These devices contain air and are added as “T” sections in different areas. When the water is off, rather than “bang,” it attempts to force itself into the “T,” stopping the noise.

In addition, depending on the type of plumbing used in your home, hot water lines can make different noises as the water goes from cold to hot. We call this a thermal expansion. There are different ways to resolve this problem. Again, you will want to consult with a professional plumber to determine the most appropriate resolution for your home.

groaning pipes when toilet flushes

Work with the Experts

TIP: Do not ignore the noises your pipes are making. In many cases, your home’s plumbing is alerting you to a problem that needs your immediate attention. Ignoring it and not getting it checked out could lead to more costly plumbing repairs later.

To schedule a plumbing inspection for your Houston-area home, please feel free to contact MET Plumbing & Air Conditioning at 281-599-3336 today!

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