Outdoor faucet leaks inside house when there is back pressure.

facet needs to be replaced

There is some sort of opening between the faucet and house. Caulk well around faucet on the outside of house and the pipe coming in on the inside of the house.

You may have a crack in the plumbing behind the wall.

That would be my thoughts too Barbara, but why does it only happens when there is back pressure? There are no leaks if I turn the facet off. BTW, the house is only 1 year old... Of course right after the 1 year warranty ends... :-(

Yikes! Call a plumber to fix, and at least a handyman to help you determine what damage has occurred and to replace any rotten or moldy areas.

You need to install a "Back Flow Preventor." We had to do that when the county installed some new water lines. A lot of pressure on front line.

I am guessing that you have what is referred to as a "frost proof sill cock". Otherwise it would leak in the wall when the water is off too. That is the actual mechanism that stops the water is inside the house while the handle and outlet are outside. This is easy to replace. You just need to shut off the water to the faucet (or likely the whole house), remove any screws holding the faucet to the house, and unscrew the whole thing with the help of a pipe wrench. These come in different lengths so you'll need to take the current one with you to the hardware store. The long pipe that goes through the wall has split, probably from someone leaving a water filled hose connected during the freezing months.

If it doesn't leak into the wall without the hose connected. Any chance the rubber washer in the hose connection is worn and a water is leaking into the wall when it's off? Replace the washer and caulk around the faucet where it goes into the exterior wall.

Either cut off flow to that faucet, or locate the leak. You risk Frame damage! Thatz when it getz Expensive!

I would definitely replace the pipe and faucet from inside the house at the shut off valve to turn off the water for the winter all the way out. You could have even a pin hole just behind the faucet. When you attach a hose it creates back pressure which is probably why that is the only time it leaks. I live in a 63 yr old house and have been replacing lots of pipes in the last three years. Lived in a house before that was about 110 years old and was always having to repair pipes.

Did the suggestion from Ken work? I have this issue as well.

Hello Victor, just curious, what was your final resolution on this issue as we're experiencing the same?