Most Likely Causes (Ranked)
The rubber washer at the end of the valve stem presses against a brass seat when you close the handle. After years of use, the washer flattens, cracks, or develops a groove. Hard water deposits corrode the brass seat. The result: a drip from the spout even when fully closed. This gets worse over time as you crank the handle harder, accelerating wear.
The packing nut is the hexagonal nut just behind the handle. Inside it is a packing washer (or string packing) that seals the stem where it passes through the valve body. When this seal fails, water leaks around the stem — from behind the handle — when the faucet is on.
Anti-siphon hose bibs (required by code in most areas) have a vacuum breaker cap on top. This cap has a small rubber gasket and check valve. When they fail, water spits or leaks from the top of the bib when the faucet is on, especially with a hose attached.
Standard (non-frost-proof) hose bibs can freeze in winter, cracking the brass body or the copper pipe behind it inside the wall. The damage may not be apparent until spring when you turn on the water and water floods inside the wall. Frost-proof bibs can also fail if a hose is left connected (trapping water inside).
Brass hose bib bodies last 20-30 years. Cheaper zinc/pot-metal bibs corrode in 5-10 years. The threads where the hose connects can strip, and the body itself can develop pinhole leaks from dezincification (a corrosion process in brass).
How to Fix It
Replace the Washer
$1-3 DIY- 1Turn off the water supply to the hose bib (inside shut-off valve or main shutoff).
- 2Remove the handle screw, pull off the handle. Unscrew the packing nut, then unscrew the entire stem from the valve body.
- 3The washer is at the bottom of the stem, held by a brass screw. Remove and replace with a matching size.
- 4Coat the new washer with silicone grease. Reassemble in reverse order. Open the faucet before turning on the water supply to prevent water hammer.
Tighten or Repack the Packing Nut
$0-3 DIY- 1If water leaks around the handle: try tightening the packing nut (the hex nut behind the handle) a quarter turn clockwise with a wrench.
- 2If that doesn't work, remove the nut, pull the old packing washer, and install a new one ($1-2). Alternatively, wrap the stem with 3-4 turns of graphite packing string ($3).
- 3Don't overtighten — you need the handle to turn smoothly.
Replace the Hose Bib
$15-40 DIY / $150-300 Pro- 1If the body is cracked or corroded, replace the entire bib.
- 2Turn off water inside. Unscrew the old bib from the pipe (it's threaded onto a nipple through the wall).
- 3Apply Teflon tape to the nipple threads and screw on the new bib.
- 4For frost-proof bibs: the entire stem assembly slides through the wall — replacement is straightforward but the bib is longer.
When to Call a Professional
ALWAYS disconnect hoses before winter — even frost-proof bibs will burst if a hose traps water inside.
If you find frost damage, the repair involves opening the wall from inside to access the pipe — budget $500-2,000 for a plumber.
If your home has an interior shut-off valve for the hose bib, close it each fall and open the exterior bib to drain residual water.
Leaving a dripping hose bib over winter invites freeze damage — fix it before the first freeze.
How to Prevent It
Disconnect all hoses in fall, even from frost-proof bibs.
Close the interior shut-off valve each winter if your home has one.
Replace washer and packing every 5-7 years proactively ($3 total).
Wrap non-frost-proof bibs with insulated covers in winter ($5-8).
Frequently Asked Questions
The valve seat is 6-12 inches inside the wall in heated space, so only the empty pipe section is exposed to cold. They still freeze if a hose is left connected (trapping water).
With a hose connected and closed, back-pressure builds up. Disconnecting the hose relieves the pressure. The drip indicates a failing vacuum breaker or washer.
Yes if you're in a freeze zone. Woodford Model 17 ($20-35) is the industry standard. Installation is $100-200 for a pro or intermediate DIY.
Only if you can shut off water inside. The repair itself is the same. If you can't shut off water, call a plumber — they have specialized freeze valves.