You turn the outdoor spigot, and water shows up somewhere it shouldn't. Not from the hose end — from behind the handle, or through a crack in the faucet body, or right at the wall. The flow is fine. The moment you shut off the handle, the dripping stops. So you tell yourself you'll deal with it later and leave the hose connected all summer.
Bad call. That's usually what makes the problem worse.
A leak that only happens when the faucet's running is telling you something specific. Handle, faucet body, wall penetration, anti-siphon cap — each spot points to a different failure. Some you can fix in fifteen minutes with a wrench. Others mean a freeze cracked the brass body last winter, and the whole thing needs to come out before the next cold season.
| Where the leak appears | Most likely cause | DIY possible? |
|---|---|---|
| Around the handle or stem | Worn packing nut or packing material | Usually yes |
| From the brass faucet body itself | Freeze crack or corrosion pitting | No — replace the faucet |
| At the wall where it meets the house | Loose fitting or failed pipe joint | Plumber needed |
| At the hose-end opening | Cracked spout end or corroded threads | Replace the faucet |
| From the small cap on top of the body | Failed anti-siphon vacuum breaker | Yes — small part swap |
Why a leak that only shows up under flow is different from one that drips when it's off
A drip from the spout when the faucet is completely off? That's a worn seat washer or O-ring — the seal that's supposed to hold when the water is stopped. Different problem, different fix.
What you've got is a flow-pressure failure. The water isn't breaching a closed seal — it's finding a gap that only opens once pressure fills the line. Packing that dried out over a PA winter won't betray itself until the stem is turning under load. A hairline freeze crack in the brass is invisible when dry. The same anti-siphon diaphragm that sits quietly in a closed position will spray the moment there's flow pressure behind it.
Run the faucet and watch exactly where the water appears. A flashlight and ten seconds under pressure will tell you more than any guessing.
What worn packing looks like — and why it fails
The packing is the seal between the spinning stem and the faucet body. When you turn the handle, the stem rotates inside the housing — and the packing material, a cord or graphite-impregnated ring, compresses against it to keep water from riding up the shaft and leaking out around the handle. Think of it like the rubber washer inside a garden hose fitting. Fresh and pliable, it seals tight. Dry it out over a few PA winters, compress it unevenly for a few seasons, and it stops doing its job.
Packing leaks show up right at the base of the handle stem. Water seeps out and runs down the outside of the faucet body — slow, steady, only while the faucet's open.
The fix is often straightforward. Shut off the supply line — there's usually an isolation valve in the basement or crawl space feeding that hose bib — then try tightening the packing nut, the hex nut directly below the handle, a quarter-turn clockwise. Turn the water back on and check. If that doesn't stop it, replace the packing cord. Hardware stores sell it as plumber's packing for a few dollars, and the whole job takes about ten minutes once the water's off.
Freeze cracks — the cause most homeowners miss in spring
This one is common in eastern Pennsylvania, and the damage always happens months before anyone notices.
Frost-free hose bibs — the type installed on most homes built after the 1980s — are designed so the actual shutoff valve sits 6 to 12 inches inside the heated wall. When you turn the handle off, the water column in the exterior portion drains out automatically through a small hole in the stem. The body stays dry. Doesn't freeze.
Except when a hose is left connected.
A connected hose blocks that drain hole. The water can't evacuate. Come January, it freezes, expands, and splits the brass casting or cracks the long interior stem tube from the inside. The damage looks like nothing — a hairline, invisible when dry. Come April, you open the faucet, pressurize the line, and water sprays directly through the body of the faucet itself.
That's not a repair. Cracked brass under pressure doesn't patch. The faucet needs to come out and get replaced with a new frost-free bib — ideally one matched to your wall thickness so the shutoff point actually sits inside the heated house and not in the wall cavity. A bib with a 4-inch stem on a 6-inch wall still leaves the shutoff exposed.
How anti-siphon valves fail
Look at the top of your outdoor faucet body. There's usually a small cap — plastic or brass — with a rubber diaphragm inside. That's the anti-siphon valve, also called a vacuum breaker.
Its job is backflow prevention. When you shut off the faucet, the diaphragm opens a vent hole that breaks the vacuum in the line — stopping water from being siphoned back out of a connected garden hose, along with any fertilizer, soap, or contaminated water sitting in it, and pulled back into your home's drinking supply. The rubber diaphragm hardens over time, especially with temperature cycling. When it cracks, water sprays from the cap every time you run the faucet.
Looks alarming. It's a $5 fix. Anti-siphon caps thread directly onto the faucet body and take about two minutes to swap out.
But don't remove the cap and leave the hose bib without backflow protection. That creates a direct path from your garden hose into your water supply. Replace the cap — don't ditch it.
When the leak is at the wall
Water appearing at the exterior wall — right where the faucet escutcheon plate meets the siding or masonry — isn't a faucet problem. It's the connection between the faucet shank and the supply pipe behind the wall.
On older homes in this area, that's usually a soldered copper joint. If the solder cracked from age, movement, or a freeze event, water seeps out at the fitting when the line is pressurized. The faucet body may look fine. The failure is 2 or 3 inches behind it in the wall.
Addressing that means accessing the basement or crawl space directly behind the penetration, cutting the damaged pipe section, and re-soldering or re-fitting the joint. Not a difficult repair for a plumber. But it's not a reasonable DIY job if it means working inside a tight crawl space or opening the wall cavity.
What to check before assuming you need a whole new faucet
Before calling anyone, spend two minutes tracing the leak properly.
Run the faucet at full flow with a flashlight in hand. Is the water coming from below the handle (packing), through the brass body (freeze crack), from the top cap (anti-siphon), at the hose connection end (corroded threads), or behind the escutcheon plate (wall fitting)? That answer tells you whether you're looking at a $5 fix or a faucet replacement.
Try tightening the packing nut first — quarter-turn clockwise — and retest. It's the easiest possible fix and often all the faucet needs after sitting dry all winter. And if the leak is coming through the brass body itself, nothing you tighten will stop it. That faucet is done.
When replacing the faucet is the right call
Body cracks, corroded threads at the hose end, and standard non-frost-free bibs on exterior PA walls all point to replacement over repair.
A standard hose bib — one where the valve and seat are right at the wall, short stem — has no freeze protection built in. The shutoff happens at the exterior, so whatever water is left in the faucet is directly exposed to outside temps. On a house with an uninsulated wall cavity, that fails every few winters. Replacing it with a properly sized frost-free bib while the supply line is already shut off is worth it — the parts and labor are modest compared to dealing with a split pipe inside the wall.
Stem length matters. Frost-free bibs come in 4, 6, 8, 10, and 12-inch stems. Match the stem to your wall depth so the shutoff seat sits inside the heated envelope of the house, not at the outer boundary of it.
One more cause that's easy to overlook: high water pressure
Most outdoor faucet problems trace back to worn parts or freeze damage. But if you've replaced the packing, the body looks fine, and you're still getting leaks — especially if other fixtures in the house are showing similar wear — high water pressure may be what's actually grinding things down.
Normal residential pressure runs between 45 and 80 PSI. Push it above 80 and the constant stress on washers, packing, and O-rings chews through them faster than normal use would. A spigot running at 100 PSI doesn't last as long as one operating at 60. And the extra pressure tends to show up first at outdoor fixtures, because they're often the last stop on the supply line with no extra protection downstream.
A water pressure gauge screws onto any hose bib and gives you a reading in about ten seconds. A few dollars at any hardware store. If it comes back above 80 PSI, the real fix is a pressure regulating valve on the main supply line — not another packing swap. Most homes built in the last 20 years have a PRV already. Plenty of older homes in Berks and Montgomery Counties don't.
Frequently Asked Questions
That pattern points to packing failure, a freeze crack, or a failed anti-siphon cap — problems that only show under flow pressure. A faucet that drips when fully shut off has a different issue: a worn seat washer or O-ring inside the valve body. The two leaks look similar from a distance but require different repairs.
Yes, and it's one of the most common causes of spring hose bib leaks in eastern PA. Frost-free bibs drain themselves automatically — but only if the hose is removed first. A connected hose blocks the drain hole. Water stays in the faucet body, freezes, and cracks the brass casting or the interior stem from the inside. The damage doesn't show until you pressurize the line in spring.
Tightening the packing nut is a reasonable DIY repair. Turn off the supply line in your basement or crawl space first, then tighten the large nut below the handle a quarter-turn clockwise. If that doesn't stop it, you can replace the packing cord — hardware stores sell it as plumber's packing for a few dollars. The whole job takes about fifteen minutes once the water is off.
That's the anti-siphon valve, and it's a simple fix. The rubber diaphragm inside the cap has hardened and cracked. Replace the cap — they're a few dollars and thread right onto the faucet body. Don't remove it and go without one. It prevents garden-hose water from siphoning back into your home's supply.
Packing leaks appear at the base of the stem, just below the handle, and water runs down the outside of the faucet. A body crack shows as water coming directly through the brass housing itself — often a thin stream or spray from the casting when the line is pressurized. Run the faucet and hold your hand near the body. You'll feel where it's coming from within a few seconds.
For most homes in this area, yes. Temperatures in this part of PA regularly drop into single digits in January and February, and pipes in exterior walls or uninsulated crawl spaces are vulnerable. A frost-free bib with the right stem length for your wall eliminates most of the freeze risk — as long as you disconnect the hose every fall before the first hard freeze.
A faucet that only leaks when it's running is one of the easier outdoor plumbing problems to nail down. The water is pointing right at the failure. Packing repairs and anti-siphon cap swaps are quick DIY fixes. Freeze cracks and wall-fitting failures belong in a different category — those need a plumber and a proper replacement before next winter, not after.