A few days ago we noticed loud vibrations coming from an external wall in the house. The vibrations were becoming more frequent (like every few minutes) so yesterday I ruled out electric but shutting off the main breaker and confirming that the vibrations still occurred. I then shut off the main water valve on the outside of the house and the vibrations stopped (I waited about an hour). Once I opened the valve the vibrations started again. Last night, because the vibrating wall is next to our bed, I closed the valve so that the vibrations would not interrupt my sleep (it did quite a bit the previous night). The vibrations stopped and this morning I reopened. Since that time (it's been about 6 hours now) I've used the shower, toilets and sinks and the vibrations have not returned (I'm almost afraid to jinx it)? I was planning to call a plumber today, but I'm wondering if the vibrations might have been due to a some sort of pressure build-up that has been relieved by shutting the main valve overnight? Is that possible? Any ideas appreciated.

Thanks in Advance,
Gonzo



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If it returns, I'd try closing the supply valve on the toilet(s).

It COULD be the toilet, but if so it should happen again after you flushed the toilet. GO outdoors and check your hose faucet to see if you left it turned on when you were done with the hose.

Thanks for the responses. So far the vibrations have not returned. I found this information on another site:

To eliminate a water hammer, you need to replenish all the air chambers with air. You can’t inspect the air chambers, so this procedure is a must whenever you notice a faint noise in the pipe:

Shut off your home’s main water supply valve.

Open the highest faucet inside your house.

Find the lowest faucet on the property — it’s usually on the first floor somewhere outside or in the basement — and turn it on to completely drain all water from the pipes.

As the water drains from the pipes, air automatically replaces it.

The moment the water is completely drained from the piping, turn off the lowest faucet and reopen the main valve.

Air pushes out of the horizontal and open vertical water lines, sputtering as it exits the faucets inside. However, air remains in the air chambers, eliminating water hammer.

the typical 1/2" diameter by 9-12" long air chambers once built into home plumbing have generally been found to be useless as they are way too small, become waterlogged, and will NOT drain by gravity as they are (ironically) air bound


now, if they were 2" x 24" with accessible drain and vent valves for 'recharging'



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"Measure Twice & Cut Once" - Retired U.A. Local 1 & 638

You could follow that procedure from now until eternity and it would NOT produce the desired results, but YOU do not even know IF you have air chambers. Even if you did, they would not have produced the sounds you heard.



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Darn it!....I guess there's no sense in putting the surplus bathisphere in the attic.

It would be too heavy anyway. Put it outdoors and use it for a gerbil wheel. A BIG gerbil.

Good point - I don't know if I have air chambers. I'm not even sure what water hammering sounds like, I was just making a guess based on the fact that closing the main valve overnight seems to have resolved this issue, at least temporarily. The house was built in 2004, does that give a clue as to whether or not it's likely to have air chambers? I checked all of the outside hoses and none were running. What else could account for this behavior?

Thanks.

What you have, or had, is not water hammer.Water hammer is a single bang, when a valve closes quickly.You have water moving through a pipe at a certain velocity. You abruptly stop the movement of the water, and the pipe absorbs the momentum, and bangs against something.

Ah, okay. Thanks for the explanation.



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Impossible to tell, especially since it is gone and can't be duplicated to see what starts it. Air chambers depend on whether the plumber wants to put them in or not, but you probably DO NOT have them.