The Different Plumbing Noises and What They Mean

Home Plumbing Troubleshooting

The Different Plumbing Noises and What They Mean

Plumbing noises are something you just don’t want to hear. Ideally, you shouldn’t expect to hear anything coming out of your pipes except running water. If you think your pipes are haunted, don’t be afraid! There are no ghosts living in your pipes, just solvable plumbing issues. Here are some noises you might hear sometimes coming from your home’s pipes.

Knocking When You Shut off the Water

It might sound like your pipes are trying to get your attention whenever you hear knocking sounds coming out of your plumbing, but there are a few reasons why this may be occurring. Sometimes, you may hear knocking just as the water supply is shutting off such as when the washing machine has finished filling up, or a toilet stops flushing. This is a phenomenon known as “water hammer”. Water hammers take place whenever running water encounters a valve that is closed suddenly, resulting in heavy vibrations and a hammer sound. This is usually the result of a worn-out hammer arrestor in the pipes. The problem could be that the builder never installed a water hammer arrestor. Houses built before 1970 face this issue more commonly.

Knocking When the Water Is Running

If the water is running while a hammer noise is occurring, it’s probably due to unusually high water pressure within the plumbing system. A water pressure gauge can be used to test the pressure, and if it’s too high, you’ll need to call a plumber in to replace or repair the pressure reducing valve.

Random Knocking

It’s bad enough when there’s knocking while the water’s running, but sometimes, you’ll hear a knocking sound occurring throughout the day. This is usually the result of sediment buildup in the water heater. An increase in sediment can cause the water heater to vibrate, and this can extend to the pipes in the walls. Flushing your water heater removes the sediment and should resolve the problem.

Dripping Sound

You may become so used to the sound of a dripping faucet you forget it’s even happening. Don’t let it go unaddressed! It might not seem like much, but the costs of a leaking faucet can add up.


Take note if you hear a gurgling sound taking place when the toilet flushes, or water runs down the drain. This could be an indication of bubbles trapped in a pipe, a clog building up, or even sewer line issues. The gurgling itself may not seem like much, but it could be a sign of bigger, more expensive problems to come if left unresolved.


Squeaking or whining sounds coming out of your plumbing is probably a sign of a depleted pressure-reducing valve. This could affect the entire house, or be isolated within your bathroom or kitchen. In the worst-case scenario, a failing pressure-reducing valve could result in burst pipes, so you should definitely call in an expert.

Being familiar with the different kinds of sounds coming out of your plumbing can help you be more aware of plumbing problems as they evolve. Calling in a plumber before a problem gets out of hand is the best way to avoid expensive repairs.