Was at someones house other day, they showed me that when they turn on just the hot water line by slowly turning the knob that you hear this rapid thumping/grinding like sound in the water line. It also happens on the cold as well, not as bad. This just developed in their plumbing lines. I am told that the water company has been increasing water pressure a little in the area, could this be the cause? And is this truly water hammer? If so it’s gonna be murder trying to find a place to push cushion pipes, every dang thing is enclosed.
If at first you don’t succeed, try using a hammer next time…everything needs some extra persuasion from time to time. -ME
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Sometimes that can be solved by installing check valves just upstream of the offending fixture. Also, there are hammer arrestors that can be installed at the washing machine outlets and probably at other fixtures as well, just prior to the angle stops. If the water pressure is more than about 80 lbs. I would consider a pressure reducer on the incoming water service. For that matter there may already be one and it simply needs to be dialed back. A good plumber can help.
I saw on TOH where they had a groaning, vibrating noise that was caused by the toilet fill valve. The valve had a washer that was vibrating like a reed in a woodwind instrument. This happened mostly when hot water was turned on, not when toilet was flushed. Trethuey said it was that the overall pressure in the lines changing made this valve washer flutter. Solution was to replace it.
I may be wrong, but thought hammer occured mainly when shutting a faucet off?
I have it, and am struggling to pin point the exact source. Bought the house last year in may, wasn't present then. This year, mild winter (northern CA) hammers present and hard. Mine isn't from a fixture however, but from the sprinklers changing zones.
Generally the water is turned off slow enough at the faucets to cause no issue, the gate valves for the zones though is so rapid, it's like slamming the door (so to speak).
I think the water pressure has been increased in the neighborhood and have since dialed back the water main valve instead of wide open (and it seems to have had a positive effect).
It's certainly a challenge though, hope you find it and find a decent solution soon.
Mike
In your case, either a pressure reducer on the house or a water hammer arrester located near the sprinkler valve would likely eliminate the problem.
Yeah, I think you're dead on Dan.
Issue is that the plumbing for the sprinklers is underground and T's right from the water main outside the house (really, really bad design). If I do this, I'll likely replumb and add a vacuum valve to do it right.
It's worth it, compared to the annoying noise and possible consequences... but, argh, what a hassle.
Cheers,
mike
Placing a hammer arrestor on the main line right after it enters the house may provide some symptomatic relief.
That's not literally water hammer, though a hammer arrestor may help.
The problem is occurring because of resonance in some valve in the system, likely either the valve you're operating or a pressure reducer or backflow valve near where the water enters the house.
The resonance is caused, in turn, by some part in a valve that is vibrating in the water flow or, in the case of the pressure reducer, sticking slightly.
If there is a pressure reducer valve in the house (near where the water comes in, it's a funny-looking valve with a sort of conical body and a longer than usual valve stem, usually with a T handle rather than a knob), then adjusting the valve a little (a quarter turn or so) one way or the other may "cure" it.
It can be as easy as checking the washer in your tap. The set screw holding the washer may be lose.