How to Replace a Frost-Proof Hose Bib
Updated March 2, 2026
Replace a leaking or frozen outdoor faucet with a frost-proof sillcock that shuts off water inside the heated wall -- preventing frozen pipe bursts.
Overview
A frost-proof hose bib (sillcock) has a long stem that extends 6-12 inches through the wall. When you turn the handle outside, the actual shut-off point is inside the heated space -- where it cannot freeze. Standard hose bibs shut off at the exterior wall, leaving water in the pipe between the valve and the outside. That water freezes and bursts the pipe inside the wall. If your outdoor faucet drips, will not shut off, or has frozen and burst, a frost-proof replacement prevents it from happening again.
What You'll Need
Safety First
- Turn off the water supply to the outdoor faucet before removing it. The interior shut-off valve is on the pipe feeding the hose bib, usually in the basement or crawlspace.
- The sillcock extends through the wall at a slight downward angle (toward the outside) so residual water drains out instead of sitting in the pipe. Verify the angle during installation.
- If the pipe behind the wall is copper and the new sillcock connection is threaded, you need a threaded-to-solder adapter. Do not solder directly to the sillcock -- the heat damages the internal washer.
Step-by-Step Instructions
- Shut Off Water and Remove the Old Hose Bib
Close the interior shut-off valve for the outdoor faucet. Open the outdoor faucet to drain residual water. From inside, disconnect the old hose bib from the supply pipe. If it is threaded: use two wrenches (one on the pipe, one on the sillcock) and turn counterclockwise. If it is soldered: cut the pipe 2-3 inches behind the solder joint with a tube cutter. From outside, pull the old sillcock out through the wall. The hole through the siding and rim joist should be visible.
Tip: Measure the wall thickness before buying the replacement. Standard sillcocks come in 6, 8, 10, and 12-inch stem lengths. The stem must be long enough to extend from the exterior siding through the wall to the interior pipe connection. Too short and the shut-off point is in the cold zone. Too long and the stem protrudes too far inside. - Install the New Frost-Proof Sillcock
From outside, insert the new sillcock through the wall hole. The sillcock should angle slightly downward toward the outside (1/4 inch per foot of stem length). This ensures water drains out when the faucet is closed instead of sitting in the stem and freezing. From inside, connect the sillcock to the supply pipe. Threaded connection: Teflon tape on the threads, hand-tight plus one turn. Soldered: solder a coupling to the pipe and the sillcock adapter (do not apply heat directly to the sillcock body). SharkBite: push-fit connection, no tools needed.
Tip: The downward angle is critical. A level sillcock traps water in the stem. That trapped water freezes in winter. A slight downward pitch toward the outside lets gravity drain the stem every time you close the faucet. - Seal and Secure
From outside, slide the mounting flange over the sillcock and against the siding. Screw the flange to the wall with the included screws. Apply exterior-grade silicone caulk around the flange where it meets the siding -- this prevents water and air infiltration through the wall penetration. From inside, verify the pipe connection is leak-free. Turn on the interior shut-off valve. Open and close the outdoor faucet several times. Check all connections for drips.
Tip: Caulk the exterior flange thoroughly. The hole through the wall is a direct path for cold air to reach the interior pipe. Air infiltration at the sillcock penetration is a common cause of frozen pipes in the adjacent wall cavity.
Pro Tips
- Woodford Model 19 and Prier P-164 are the two most popular residential frost-proof sillcocks. Both are available in 6-12 inch lengths, brass construction, and anti-siphon models (required by code in most areas to prevent contamination of the water supply from a connected garden hose).
- Anti-siphon (vacuum breaker) models are code-required in most jurisdictions for any hose bib. They prevent water from a garden hose, sprayer, or fertilizer applicator from being sucked back into the drinking water supply if pressure drops. The vacuum breaker is a small device built into or attached to the top of the sillcock -- look for it when buying.
- After closing a frost-proof sillcock in fall, disconnect the garden hose. A connected hose traps water in the sillcock stem and prevents drainage. The trapped water freezes and splits the sillcock -- defeating the entire purpose of the frost-proof design.
- If your house has multiple outdoor faucets, replace them all with frost-proof models at the same time. The plumber is already on-site, and the incremental labor for each additional sillcock is $50-$100 vs $150-$300 for a separate visit.
- A frost-proof sillcock with a locking handle ($25-$40) prevents unauthorized water use. The handle requires a key to operate. Useful for rental properties and homes with exterior access points.
When to Call a Pro
Call a plumber if the interior pipe is galvanized steel (threading and fitting requires pipe wrenches and skill), if the wall penetration needs enlarging (drilling through brick, stone, or concrete), if the sillcock connects to a pipe inside a finished wall with no access panel (wall opening may be needed), or if you want anti-siphon compliance verified to meet local code.
Frequently Asked Questions
When should I call a plumber to replace a frost-proof hose bib?
Call a plumber if the interior pipe is galvanized steel (threading and fitting requires pipe wrenches and skill), if the wall penetration needs enlarging (drilling through brick, stone, or concrete), if the sillcock connects to a pipe inside a finished wall with no access panel (wall opening may be needed), or if you want anti-siphon compliance verified to meet local code.
What are some expert tips to replace a frost-proof hose bib?
Woodford Model 19 and Prier P-164 are the two most popular residential frost-proof sillcocks. Both are available in 6-12 inch lengths, brass construction, and anti-siphon models (required by code in most areas to prevent contamination of the water supply from a connected garden hose). Anti-siphon (vacuum breaker) models are code-required in most jurisdictions for any hose bib. They prevent water from a garden hose, sprayer, or fertilizer applicator from being sucked back into the drinking water supply if pressure drops. The vacuum breaker is a small device built into or attached to the top of the sillcock -- look for it when buying. After closing a frost-proof sillcock in fall, disconnect the garden hose. A connected hose traps water in the sillcock stem and prevents drainage. The trapped water freezes and splits the sillcock -- defeating the entire purpose of the frost-proof design. If your house has multiple outdoor faucets, replace them all with frost-proof models at the same time. The plumber is already on-site, and the incremental labor for each additional sillcock is $50-$100 vs $150-$300 for a separate visit. A frost-proof sillcock with a locking handle ($25-$40) prevents unauthorized water use. The handle requires a key to operate. Useful for rental properties and homes with exterior access points.
What tools do I need to replace a frost-proof hose bib?
You will need: Frost-proof sillcock ($15-$40, matched to your wall thickness), Tube cutter (if cutting copper pipe for the interior connection), Two pipe wrenches or adjustable wrenches (for threaded connections), Teflon tape (for threaded connections), Exterior-grade silicone caulk (for sealing the wall penetration), Level (to verify the slight downward pitch toward the outside), Screwdriver (for mounting the exterior flange).
When should I call a professional instead of doing this myself?
Call a plumber if the interior pipe is galvanized steel (threading and fitting requires pipe wrenches and skill), if the wall penetration needs enlarging (drilling through brick, stone, or concrete), if the sillcock connects to a pipe inside a finished wall with no access panel (wall opening may be needed), or if you want anti-siphon compliance verified to meet local code.
How difficult is this project?
This project is rated intermediate. It requires moderate DIY skill and the right tools.
How long does this take?
Plan for approximately 45 - 90 minutes. First-timers may need extra time.
How much will this cost?
The estimated cost is $15 - $40 for the sillcock; $150 - $300 with a plumber. Costs vary by location and materials chosen.