How to Stop Noisy Water Hammering in Your Pipes
Noisy water pipes are a common source of annoyance, particularly in older homes. We may have grown accustomed to the abrupt sound of water hammering behind the walls every time we turn the faucet off, but it doesn’t have to be a permanent fixture in your home. Here are a few ways to locate and stop the source of noisy water pipes in your home.
Drain all the plumbing in your home
A frequent noise caused by water pipes is called water hammering which occurs when you turn a faucet off and all the water rushing through the pipes is forced to come to an abrupt halt. Normally, this is mitigated by an air cushion or chamber, which is the vertical pipe behind the faucet which gives rushing water a place to go after the taps are turned off. However, over time, the air in this vertical pipe can become depressurized or waterlogged, and new air needs to be restored to the pipe by draining all water in your house.
Next, turn off your water main and begin by opening all your faucets, starting with appliances and faucets at the highest level of your house (top floor) and working your way down to the first floor or basement. Remember to flush your toilets, too. Then wait half an hour with all the faucets open to thoroughly drain. Next, turn back on your water main. This should help restore air to the chambers and reduce the banging sound when you turn off your taps.
Clean or replace the air chamber
This vertical pipe may have simply build up too much scale or residue over time, and draining to restore air flow may not solve the problem. In this case you’ll need to remove the cap to the chamber and clean out the pipe manually to make sure there’s a place for rushing water to flow.
Reduce the water pressure — for globe valves only
If you’re still experiencing water hammering after performing the previous steps, you may need to reduce the overall water pressure in your house, because eventually the rushing water pressure could damage your pipes or even cause a pipe burst.
If your main water supply uses a globe valve, this is an easy fix. Simply turn the valve clockwise slightly to reduce the flow of water to your house. Check your faucets to see if the hammering sounds continue, and keep turning clockwise as needed.
Install a water pressure reducer valve
If your water main doesn’t use a pressure-regulating globe valve (and many homes don’t — they have ball or gate valves which only operate as open or closed), you may need to install a pressure reducer valve at your water main. Since this involves soldering, we recommend using an professional plumber for this.
Install air chambers or other devices
If lowering your water at the main results in faucets and fixtures running at barely a trickle, your problem may not be high water pressure. It’s possible that your home may not be outfitted with air chambers, and you may need to install them. If this involves removing part of the wall to get access to the plumbing, seek advice from a plumbing supply store or a professional plumber. There are often work-around devices you can use before tearing into a wall. A Flo device, for example, will alert you to any water pressures issues before it leads to leaks, burst pipes or water damage.