Knocking water pipes seem to be a mystery to many homeowners. One day the knocking sound may occur, but each day the knocking will get louder. Although there is nothing seriously wrong with your pipes, the knocking sound is an unnecessary irritant. The fix for knocking water pipes is so easy that you’ll want to try it right away. It doesn’t require a plumber or any new parts, and you should be able to fix it in less than 20 minutes.
Knocking pipes occur because the water supply pipes in your home are under pressure. This is required so your plumbing system can function. In addition to the pipes that carry the water, there are air chambers built into the pipes that cushion the pressure when you turn on the faucet.
The knocking occurs when the air in the pipes naturally depletes. When you turn on the faucet without the normal amount of air in the pockets, the water slams into the air or the end of the pipe, producing the dreaded knocking sound.
To eliminate the sound, start by turning off the main water valve in your house. Be sure to do this when all plumbing is in the off position of your home; shutting off the main water valve will stop any water from entering your home.
Next, turn on all of the faucets and flush every toilet in your home to drain the plumbing. Do this for as long as it takes to stop any water from coming out. When you are certain everything has been drained as dry as possible, shut off all of the faucets.
Then go back to your main valve and very slowly turn it back on. The knocking sound should be eliminated, because you have allowed the air compression chambers to refill with air.
This fix may seem deceptively easy, but most home improvement projects are easily completed one you understand the mechanics involved. If the only thing preventing you from completing this knocking plumbing fix is locating the main valve, look for the main valve in a basement if you have one. Other common locations are near the water meter outside or in the garage (if your garage is connected to your house). All of your pipes should lead to the main valve, so follow them if you can’t find the valve any other way.