OK, I just flushed the toilet and listened.

The rattling, shaking noise in the pipes does not happen as the water is being used. That part is still true.

But the sound is definitely coming from under the floor in the kitchen and in the family room, which is next to the kitchen and between the kitchen and the bathroom.

If you call a plumber they are going to charge you a service call and stand there for an hour, I guarantee you nothing will happen until he or she is just left.

Do you have an air admittance valve below the sink or somewhere in the home?

Often air that builds up in the system will vent itself and while venting it causes the water hammer effect without opening and closing a line. This can, and it is rare, without a mini vent or a AAV.

Also are you on municipal water or is it pumped from well or cistern?

It looks like someone is going to visit below the home, DO NOT go under there without someone else standing guard. It can be hazardous and based on it's construction could be a confined space, especially if a gas line exists.

This post was edited by SouthernCanuck on Thu, May 2, 13 at 2:18

"Often air that builds up in the system will vent itself..."

AAVs only allow air to ENTER the DWV system.

They NEVER allow anything to escape (unless they are broken).
Anything coming out would be sewer gas and smell horribly and possibly be flammable (as in build up and blow up the building flammable).

There is rarely enough pressure in a DWV system to move drain line move.
Falling water is about the most energetic thing going on.

Suplly lines have water pressure all the time.

The water has momentum when it is moving, and a fast closing valve can allow this momentum to transfer as pressure spikes to the pipes and create water hammer (an actual pressure spike that can make pipes move and cause damage to pipe joints not designed for moment, or even exceed the pressure rating of the plumbing).

"When it happens, no water is being used anywhere in the house. "

Close your main cutoff and see if the nose goes away.

That would mean it is NOT water hammer (no water moving, no water hammer will occur, especially with no pressure actually available).

I asked about the AAV brickeeye because I'm thinking it might be opened slightly allowing air to ENTER the system.

So what is your solution besides proving it's not water hammer or constantly spending time and effort to continually prove others wrong. I'm really getting tired of your constant corrections of others. Get outside and get some fresh air.

There I've finally vented after months of reading your posts. I will not respond hereafter.

I hope I didn't spell anything wrong.

" I'm really getting tired of your constant corrections of others. "

I am really tired of dumb suggestion like a working AAV venting.

Thanks for the info.

I have absolutely zero experience wtih or knowledge of how to fix things around the house, so asking if I have an air admittance valve or telling me to close the main cut-off means zilch.

I haven't heard it for several days now. My original post was May 1, and it is now May 5.

I was thinking my best way to handle it might be to get my phone out next time it happens and try to get a recording of the sound, and then show it to a handyman or plumber.

Thanks for the input, though.

If you know nothing about home repair you must have someone show you where the main shut off valve for your water supply is. It can save thousands of dollars in damages if you " spring " a leak and have to wait for someone to shut it off for you.

An AAV would be the last thing I would suspect to cause such noise. More likely is a toilet with leaking flush valve flapper that causes the fill valve to operate briefly at unexpected moments.
Is your supply from a well or municipal source?

I had the same thing. Could go months without happening, and then could occur many times. It would sometimes wake me up. I have a permanently installed pressure gauge in the garage, and the pressure would be pulsing about twice a second, with about 4psi variation. Had the city out a couple of times, one of which I was lucky to have the event going. No resolution. I'm thinking that maybe whatever pump pushes water uphill to the holding tank was still going when it was full, causing the pulsing.

Edit: Just re-read your description. Have you been in the bathroom when the noise was going? Your description does sound a lot like a bad/oscillating toilet flapper valve.

Try adding a pressure gauge (just screw one onto a hose tap), and see what you pressure is doing when the noise goes.

I added a pressure regulator during my remodel, which I expect to fix my problem, if it even occurs any more (remodel been going 2 years, moving back in soon).

This post was edited by attofarad on Wed, May 15, 13 at 2:07