Don't Wreck an Outdoor Faucet
Here's why you end up replacing outdoor faucet washers that have worn out long before they should: When you turn off a frost-proof faucet, water continues to trickle out of the long pipe even after the valve is closed. When people see that water, they often assume the valve didn't close, so they crank down harder, which overcompresses the washer, greatly reducing its life. Patience is the key. Wait a second or two after closing the valve. The water should eventually stop (unless you've already destroyed the washer).
MYTH: Frost-proof faucets cannot freeze.
FACT: Leaving a hose attached throughout the winter could leave water in the line to freeze and cause the faucet to burst. Also, if the faucet slopes slightly toward the house, the long pipe will also hold water that can freeze.
Plus: Winter Preparedness: Handy Household Tips for Weathering the Winter