Hi folks. I’ve been doing some research online but I thought I’d check in here. As the title says, pipes in the wall rattle when a faucet is shut off.

Been happening for a week in a 25 year old house. No plumbing issues prior.

Sounds like the opposite which a hammer valve is used for.

Maybe the water system has less pressure than yours and creates a hydraulic vacuum.

quote:

Originally posted by Spokane228:

a faucet

A clue.

It only happens when one particular faucet is shut off but not when opened? The hot side of a two handled lavatory sink faucet in a second floor bathroom? But not the shower, which has a single handle faucet?

quote:

Originally posted by Woodman:

quote:

Originally posted by Spokane228:

a faucet

A clue.

It only happens when one particular faucet is shut off but not when opened? The hot side of a two handled lavatory sink faucet in a second floor bathroom? But not the shower, which has a single handle faucet?

Any sink in the house. When shut off. All faucets are single hot/cold. I’ll see if I can isolate a hot or cold line.

Water Hammer Arrestor by Oatey.

Appears to be occurring only on the hot line.

A pipe in the basement came loose? And there is an air pocket in the line somewhere?

I'd probably run all the hots at once, then have someone in the basement looking for a shaking shuddering pipe as they are turned off.

No basement (townhouse). It’s in the walls. Seems to be in the utility room with the furnace and hot water heater. It could be air? Bleed the lines?

Do you have a water hammer arrestor on your water heater/hot water line? Mine has an air valve on the top, and I "think" you have to keep some air in the tank to prevent this?

I'd check the pressure reducing valve, which is usually right after the main shut off coming into the house. They will wear out over time, and I had similar rattling/hammering until I replaced mine.

Water coming in is colder than it was a few months ago and is expanding more when it's heated by the water heater. Do you have an expansion tank inline after the water heater?

quote:

Originally posted by bubbatime:
Do you have a water hammer arrestor on your water heater/hot water line? Mine has an air valve on the top, and I "think" you have to keep some air in the tank to prevent this?

There is a diaphragm, like a basketball, inside of a standard expansion tank. The ones I use are factory pre-charged at 37 psi. If you check your pressure, and water comes out, that means the diaphragm has become compromised. You've also lost the expansion qualities of the expansion tank. A give-away: The relief valve on your boiler kicks off as water expands.

I'm unqualified to speculate if there is a connection here. While I'm pretty much out of residential work now, I never saw many expansion tanks on domestic potable water systems 'back in the day'.

If it is just one faucet, it could be as simple as a loose washer, either in the faucet itself or the supply stop to the faucet.

Possibly water hammer. Google "water hammer in house." There are directions for shutting off the main, opening faucets in certain sequence to drain the water from the pipes, then refilling.

A question I am curious about, other than the annoying rattle of the pipes, is there a consequence of NOT fixing/repairing this problem??

I had the pressure regulators go bad in 2 houses, which sounds identical to your problem.

First house it was just old, 2nd house it was a bad regulator.

This can be easily checked if you know someone who has a gauge which can be hooked up to any sink. It should be close to your main shut off valve, before the valve (I think).

Yes, this can cause problems in the future. Especially if the incoming water is under very high pressure.

I'm not a plumber, but this sounds identical to what both my houses did.

I have the same problem. After a new kitchen faucet was install the pipe rattle occurred.

If my faucet is on the north wall the rattling pipe is on the east wall above the refrigerator.