Noisy Water Pipes
Noises and Bumps in the Night
Weird noises can be caused by water flowing through pipes. Sometimes, there are additional sounds such as rattling, whistling, loud banging and creaks and cracking. In order to understand the reason for these noises, a few suggestions are listed below. Please note that these are suggestions only; your plumber should be contacted in most cases to resolve the problems.
Rattling - caused by pressure of water running through a loosely attached pipe, causing the pipe to vibrate slightly. To fix the rattle, simply stop the pipe from vibrating. Put some cushioning or insulation around the pipe or fasten the strapping more securely so the pipe won't vibrate.
Whistling - caused by water flowing through a restricted section of plumbing. The restriction can be due to sediment in the pipe or a defective washer or valve. If the whistling is isolated to a particular faucet then that's likely where the problem is - replacing the washer or repairing the valve should resolve it. If the whistling is throughout the house when any faucet is turned on then the problem is more likely in the main water supply valve. Adjusting the water pressure at the main water valve may dislodge the impediment or the change in pressure may stop the whistling. If neither of these remedies work, you may need to replace the water valve.
Loud Banging - this is actually called a "water hammer" and typically occurs in older homes when you shut off the water flow. Initially a home's plumbing system was built with short pieces of pipe that filled with air and acted as air cushions to absorb water's energy when the flow was abruptly stopped. Over time, the air can lead out, meaning there is no air cushion left to absorb the water energy.
In order to put the air cushion back into your plumbing system, you may wish to contact a plumber. A remedy may be to turn off the main water supply and open all the household faucets to drain the system. Then the water can be turned back on and working from one room to another, turn off the faucets as water flows through them. This should trap some air in the air chamber so it will again provide a cushioning effect. Failing this remedy, you can purchase a "water hammer arrester" that attaches directly to the water supply pipe where the water hammer is.
Creaking - caused by expansion and contraction of water pipes. As hot water runs through a pipe, it heats the pipe, causing it to expand slightly. Once the water stops, the pipe cools and the metal contracts, resulting in creaking or cracking. To resolve this, put some insulation around the pipe or, if the pipe is running through a tight hole in the wood framing, cut a notch in the framing so the pipe can expand and contract without that creaking sound.