What a frost-free faucet is and why you replace one

A frost-free faucet (also called a freeze-proof or anti-freeze faucet) is an outdoor spigot designed to drain water from the supply line when you turn it off, so ice cannot form inside and crack the pipe during winter. When one stops working — whether it leaks, won't shut off, or won't turn on — replacement is usually simpler and cheaper than repair.

The job takes 30 to 60 minutes and requires only basic tools: an adjustable wrench, a screwdriver, and possibly a hacksaw. You do not need to be a plumber. The hardest part is usually reaching the faucet or draining the line, not the swap itself.

Key Takeaways

  • Turn off the water supply to the faucet before you start — either at a shutoff valve near the faucet or at the main water meter if no local valve exists.
  • Drain the line by opening the faucet and letting water run until nothing comes out, then close it again.
  • Unscrew the mounting nut on the inside of the wall where the faucet connects, then pull the old faucet out and disconnect the supply line.
  • Slide the new faucet in, reconnect the supply line, and tighten the mounting nut from inside — do not overtighten or you will crack the faucet body.
  • Turn the water back on slowly and check for leaks at the connection point before you consider the job done.

Locate the water shutoff valve

Before you touch the faucet, you must stop water from flowing to it. Look on the inside wall behind or near the faucet for a small valve with a handle or knob. This is the local shutoff. Turn it clockwise until it stops — do not force it. If no valve exists, you will need to shut off water at the main meter, usually in the basement, garage, or outside near the street.

If you shut off the main, turn the valve at the meter clockwise. Leave a note for anyone else in the house so they know why the water is off. The whole house will have no water until you turn it back on, so plan this for a time when no one needs to use sinks, toilets, or showers.

Drain the supply line

Open the faucet handle and let water run out. This empties the line so you do not get soaked when you disconnect it. Water will flow for a few seconds, then stop. Close the handle again.

If the faucet is stuck or broken and will not open, you can skip this step, but be ready for a small amount of water to spill when you disconnect the supply line. Have a bucket or towel nearby.

Remove the old faucet from inside the wall

Go inside the house to the wall where the faucet connects. You will see the faucet body sticking through the wall, with a large nut holding it in place on the inside. Use an adjustable wrench to turn this nut counterclockwise. It may be tight — explore steady pressure rather than sudden force. Once the nut is loose enough, unscrew it by hand and set it aside.

Pull the faucet body out through the wall from the inside. You may need to wiggle it slightly. Once it is out, you will see the supply line (a copper or plastic tube) connected to the back of the faucet. Use an adjustable wrench to loosen the fitting where the line connects to the faucet. Turn counterclockwise until the line comes free. A small amount of water may drip — this is normal.

Install the new faucet

Take the new frost-free faucet and slide it through the hole in the wall from the inside, with the handle and spout pointing outward. The faucet body should sit flush against the inside wall. Reconnect the supply line to the back of the new faucet by hand first, then use the wrench to tighten the fitting. Tighten until snug — you should not be able to turn it by hand, but do not crank it with all your strength or you will strip the threads or crack the faucet.

Slide the mounting nut onto the faucet body and thread it onto the faucet by hand. Once it is hand-tight, use the wrench to tighten it another quarter turn. Stop there. Overtightening cracks the faucet body and causes leaks you cannot fix without replacing it again.

Turn the water back on and test

Go to the shutoff valve (or the main meter if you shut off the whole house) and turn the handle counterclockwise slowly. Water pressure will build. Open the new faucet handle to let air out of the line — you may hear hissing or see sputtering water. Let it run for 10 to 15 seconds, then close the handle.

Check the connection point on the inside wall where the supply line meets the faucet. Wipe it dry with a towel and watch for drips over the next minute. If water is dripping, the fitting may not be tight enough. Turn off the water again, tighten the fitting a quarter turn more, and test again. If the mounting nut is leaking, tighten it slightly, but be very careful not to crack the faucet body.

Once the faucet is dry and the handle works smoothly, the job is done. Test it a few times over the next day to make sure no new leaks appear.

What to do if the faucet won't come out

Sometimes the old faucet is stuck because mineral buildup has hardened around the supply line connection or the mounting nut is corroded. If the nut will not turn after steady pressure, spray it with penetrating oil (like WD-40) and wait 15 minutes. Try again. If it still will not budge, you may need to use a pipe wrench instead of an adjustable wrench — the wider jaw grips better on corroded metal.

If the faucet body itself is stuck in the wall, do not pull hard. Spray the outside of the faucet where it enters the wall with penetrating oil and wait. If it still will not slide out after several attempts, the hole may be too small or the faucet may be glued. In that case, you may need to use a hacksaw to cut the supply line closer to the faucet, which gives you more room to work. This is rare, but it happens with very old installations.

Frequently Asked Questions

Do I need to replace the supply line too?

No, unless it is cracked, kinked, or leaking. Most supply lines last many years. If the line is copper and looks corroded or green, or if it is plastic and brittle, replace it along with the faucet — it costs $10 to $20 and prevents future leaks.

What if water keeps dripping from the new faucet after I turn it off?

This usually means the internal valve is not sealing. Try turning the handle all the way clockwise with firm (not hard) pressure. If it still drips, the faucet may be defective. Return it and swap it for another one. Do not overtighten the handle or you will damage the valve.

Can I replace a frost-free faucet in winter?

Yes, but work quickly. Once you open the wall, cold air can enter the pipe. If you live in a very cold climate, consider doing this job in fall or spring. If you must do it in winter, have the new faucet ready before you start and minimize the time the line is open.

Should I use plumber's tape on the supply line connection?

No. Frost-free faucets use compression fittings that seal with a metal ring, not threads. Plumber's tape is for threaded connections and will not help here. Just make sure the fitting is tight.

What size wrench do I need?

An adjustable wrench works for almost all frost-free faucets. The mounting nut is usually 1 to 1.5 inches, and the supply line fitting is usually 0.5 to 0.75 inches. If you have a set of open-end wrenches, check the nut size before you start and grab the right size — it is faster than adjusting.