A Dripping Outdoor Spigot Is Money Running Down the Wall.

This one catches people out every winter, and it catches out the people who spent the money on the better spigot. A frost-free bib is a long tube with the shut off valve at the far end, deep inside the heated wall. Close the handle and the whole exposed length is supposed to drain out through the spout. That is the entire trick. A hose on the end blocks the drain, the tube stays full, and it splits inside the wall.

You will not find out in winter. The split happens while the pipe is frozen, and frozen pipe does not leak. The first warm day you go out and turn the spigot on to wash something, and the water goes into the wall cavity instead of the hose. That is why a burst bib so often turns up as a spring problem with a winter cause.

So, before the first hard freeze: take off the hose, and take off any splitter or timer left on the threads too, because those trap water just as well. If your bib is a standard one rather than frost-free, you also need to shut its interior valve and leave the spigot open to drain. And if water dribbles out of a frost-free bib for a few seconds after you shut it off, nothing is wrong. That is the tube draining, which is exactly what it is meant to do.