Water Valve Leak: Miraclous Cure?

[(PeteCresswell)]

Copper pipe to a valve under the kitchen sink.

PVC from the valve running under a sun room and to the wall of the house.

Another valve at the wall, and then maybe 20' of PVC out into the yard.

Valve under the kitchen sink leaks so even though it's shut off, there is water in the PVC over the winter and the outside PVC bursts.

Drain the system by turning off water at the meter and opening the lowest faucet in the system.

Replace the outdoors PVC.

Turn the water back on again.

Leak in the valve under the kitchen sink appears to have stopped. Came back to the property two days later, figuring maybe it's so slow that the PVC took time to fill up... but nothing.

Can anybody postulate a likely cause?

[Tony Hwang]

Hmmm, Any thing can expand and shrink by temperature. Leak when cold, no leak when warm? How come did not winterize B4 pipes burst???

[dadiOH]

What kind of valve? Did you happen to tighten the packing nut? :)

If it was a regular brass stop valve, it may have sealed from corrosion.

[(PeteCresswell)]

Per Tony Hwang:

Dunno - it's somebody else's rental property. But when he told me the story, we went over it about five times to make sure I had it right... and that he really did confirm the leak just before draining the system.

Does not jell for me - but, OTOH, I don't know anything... I was thinking maybe an experienced plumber would come right back with something in the vein of "Oh yeah, happens all the time because of x, y, and z....".

[makolber]

Here is a possible answer... If you close the inside valve and close the outside valve...then if there is even a tiny leak at the inside valve, the pipe will slowly fill up with water.

If you close the inside valve but leave the outside valve open, then any small leak at the inside valve will not be able to fill the pipe. The water will either evaporate or slowly drip out the outside valve.

So close the inside valve but leave the outside valve open.

Mark

[nestork]

Pete:

Ask the property owner if he noticed WHERE the water was leaking from. That makes all the difference here.

No plumber is going to be able to diagnose what happened to stop the leak because normally they don't stop by themselves. It very well could be that the tenant in that house simply tightened the packing nut or the

3/8 compression fitting nut to stop the leak.

[micky]

I know that all I have to do is touch something, and that fixes it half the time. Especially when I was little. Then, if I took it apart and put it back together again, that fixed it all the time, even if I didn't change anything.

But I'd go back a couple times, especially before it gets freezing out, and make sure it's not still leaking.