Water Hammer

[rwkkhart]

I could use some advice on a problem. I recently replumb my house with copper pipe and new fixtures including faucets and toilets. I am beginning to get strange noises in the early morning hours which I believe may be water hammer. The pipes make a deafening noise and then stop. This only seems to happen when the guest bathroom has been used. The strange part is that the noise does not occur directly after the bathroom has been used. It may be hours later before the noise occurs. If we do not have company and the guest bathroom is not used then there is no noise. Do you think this is a water hammer problem or could it be something else. Thank you for your help.

 

[Jadnashua]

Water hammer occurs when flowing water gets turned off quickly and the motion (inertia) of the water slams into the end of the pipe at the valve and pushes it against something that makes it bang...literally the pipe hammering into something. Normally, this only happens with fast acting valves, like those on an icemaker, washing machine, dishwasher, etc.

A toilet valve can make things groan if it is opened slightly as may occur if there is a small leak from the tank to the bowl. Turn the water off to the toilet and see if the sound occurs. then, after it has sat for awhile, check the tank to see if it is lower. If the tank empties, or drops, the seal (usually a flapper valve) needs to be replaced. SOme fill valves are more prone to making noises than others, but fix the flapper first, if that's it and see.