My house is ~8 years old (built in 2002) and recently I noticed a strange problem. In the master bedroom, and only in the master bedroom, if immediately after I turn off the faucet rapidly, or immediately after the water tank for toilet fills up, I can hear several knocking sounds from one of the wall. There are probably 4-5 knocking sounds and they fade away. It seems there is no sound if I turn off the faucet slowly, or reduce the water flow to quite slow for the toilet water tank.

I read online regarding the water hammer, and tried a few times to drain the pipes, i.e. turn off water main, open faucet at lowest point of house, and let the water drain. These trials do not appear solve the problem. At one time, the problem goes away and returns in a hour. At another time, the problem does not go away.

Any one here has some insight on what's going on? I almost have nighmares about some pipes in the wall burst, or big repair bills.

Thanks
Ken

Is it only on the cold water that bangs or does the hot side do the same thing? Back to you, Tom

It happens on either cold or hot water. Thanks Ken

Can anyone give me some answers? Thanks Ken

Pipes knocking loudly after flushing

Turn off water to house. Open all faucets, flush all toilets. Let water drain completely, if possible let sit for a while so all water drains out of air chambers. Close all faucets, turn on water. Turn on water slowly so that you don't blow out cartridges in single handle valves.