Tommy Mac Discussions › Forums › Fix-it Forum: Home Improvement & Do It Yourself Repair Forum › Loud humming from pipes › Phenomenon called Water Hammer
If you hear a thumping or banging when water stops filling the toilet tank? or when you turn water off quickly at certain faucets? or after the washing machine draws water. Its called water hammering
Before you call a plumber, first you can try this simple trick. Your plumbing system probably has air cushions. These cushions or shock absorber chambers, located near the laundry, the kitchen, or the main valve, were initially filled with air so that when a valve closed quickly, the force of the water movement bounced against the air cushion. This prevented the hammering.
Now these air cushions are probably filled with water. To solve the problem, you need to drain your plumbing system. Start by turning off the main water supply. Then open all the faucets in your home. Air will be drawn into the upper faucets. Water will drain from the lower faucets.
When water stops flowing, slowly fill the system by opening the main valve slightly. Walk through your home closing each valve as air is eliminated and a solid stream of water flows through that faucet. After you have closed all the faucets, open the main valve fully.
Now you should have an air cushion in the shock absorber chambers. If this dosn’t do the trick, buy a Water Hammer from you local plumbing suppliers and install it yourself or call a plumber. Also sediment and air may come out of the faucets for a short time.
Last thing check that piping to the washer is properly supported, because the banging can be compounded when pipes move around and hit wood framing or other objects. Adding a support may help correct the problem.