How to Replace a Frost-Free Outdoor Spigot (Sillcock)

Locate the main water shut-off valve for your house, which is typically found in the basement, a utility closet, or near the water meter. Turn the valve clockwise until it is fully closed. To drain the remaining water from the system, open the spigot you are replacing and also open the lowest faucet in the house (usually in the basement or a first-floor sink). Let the water run until it stops to relieve pressure and empty the pipes.

Go to the interior of your home (basement or crawlspace) and locate the pipe that leads to the outdoor spigot. Since we've assumed a soldered connection, you will need to heat the joint to disconnect it. Place a heat shield behind the pipe to protect the wooden sill plate or joists. Use a propane torch to evenly heat the fitting where the sillcock connects to the copper supply pipe. Do not heat the pipe itself. As the solder melts (it will appear shiny and liquid), use pliers or a gloved hand to gently twist and pull the supply pipe away from the sillcock fitting. Be cautious as the pipe will be extremely hot.

Move to the exterior of the house. Locate the mounting screws that hold the spigot's flange to the wall. Use a drill or screwdriver to remove these screws. Once the screws are out, the old sillcock should be free. Firmly grip the spigot and pull it straight out of the wall. You may need to wiggle it slightly to get it through the opening.

Take the old sillcock to a hardware or plumbing supply store to purchase an exact replacement. The most critical measurement is the length. Match the length of the new sillcock to the old one (assumed 8 inches). Also, ensure the connection type is the same (a female sweat/solder connection in this case) and that it is compatible with your pipe size (typically 1/2-inch or 3/4-inch copper). While there, also purchase lead-free solder and water-soluble flux paste if you don't already have them.

Proper preparation is key to a leak-free solder joint. First, clean the end of the copper supply pipe inside the house. Use a pipe cleaning brush or emery cloth to sand the outside of the pipe end until it is shiny and free of oxidation or old solder. Do the same for the inside of the new sillcock's sweat connection. After cleaning, use a small brush to apply a thin, even layer of flux paste to both the outside of the pipe and the inside of the sillcock fitting. Before inserting the new sillcock, open its handle about halfway. This prevents pressure from building up during soldering which could damage the internal seals.

From the outside, carefully slide the new sillcock through the hole in the wall until the flange is flush with the exterior siding. Ensure the spigot is oriented correctly, with the spout pointing slightly downwards for proper drainage. Go back inside. Push the flux-coated end of the supply pipe firmly into the flux-coated fitting of the new sillcock. Place your heat shield behind the joint. Using the propane torch, heat the fitting, not the pipe or the solder. After about 30-45 seconds of even heating, touch the tip of the lead-free solder to the seam where the pipe meets the fitting. If the joint is hot enough, the solder will melt and be instantly drawn into the joint, creating a silver ring. Apply solder around the entire joint until it is filled. Let the joint cool naturally for several minutes until it is cool to the touch. Do not quench it with water.

Once the interior joint is fully cooled, return to the outside. Align the sillcock's mounting flange so it is level and properly oriented. Using new, corrosion-resistant screws, fasten the flange securely to the exterior wall. Use a drill or screwdriver for this. Do not overtighten, as this can crack the flange. After securing the spigot, apply a bead of exterior-grade silicone caulk around the top and sides of the flange where it meets the house siding. Leave the bottom of the flange un-caulked to allow any water that gets behind it to drain out.

First, make sure the new outdoor spigot is in the closed position. Also, close any other faucets you opened to drain the system. Go to the main water shut-off valve and turn it on slowly, turning it counter-clockwise. Listen for the sound of pipes filling with water. Go immediately to the interior connection point and carefully inspect the new solder joint for any drips or leaks. Use a dry paper towel to wipe the joint, which will make even the smallest bead of water visible. Then, go outside and check the spigot itself. Slowly open the handle and let water flow for a minute to flush out any debris. Check again for leaks both inside and out while the water is running and after you shut it off.