How to Replace a Bathtub Faucet

Bathtub faucets all tend to operate the same way, but different types have slightly different configurations. Before replacing a bathtub spout, determine whether it has a slip-on or threaded design.

• A slip-on spout is made to slip onto the water stub-out pipe attached to the wall plumbing. A set screw secures the spout to the pipe.
• A threaded spout, also called a screw-on spout, has threads that fit over the end of the stub-out pipe. It doesn’t use a set screw to secure it. Instead, it screws onto the pipe for a tight fit.

Avoid plumbing work by choosing the brand, style of faucet and control handles that are already in use. A different brand or type will require opening the wall to replace plumbing parts like mixers or valves.

If you’re having trouble finding what you need, look for a brand name on the faucet or trim pieces. Take photos of the faucet and handle. Remove the handle and take a photo of the stem. Go to your local Home Depot and ask for help in the plumbing department.

Before you get started, you’ll need a few tools and supplies:

• Microfiber Cloth
• Utility Knife
• Thread Sealant Tape
• Silicone Caulking
• Adjustable Pliers
• Putty Knife
• Hex Wrench
• Screwdriver

Here are some basic tips for installing either type of bath faucet:

• Before detaching any parts, shut off the water supply to the house.
• Whether your bathtub has two handles or a single-handled design, it's installed with stems that connect to the valve or mixer. If the valve is leaking, the stem or stems may need to be repaired or replaced.
• Open the valves to relieve the water pressure in the plumbing system and then close them.
• Use a putty knife to scrape off any old caulk where the spout or handles meet the wall.
• New faucets and handles sometimes come as part of a trim kit that includes matching parts for other bath fixtures.

Tip: Cover the tub and drain with a drop cloth, towel or paint rag. This will help keep the tub’s surface from getting damaged, and it’ll also prevent screws and other small parts from going down the drain.

When removing a slip-on spout:

• Remove the set screw at the bottom of the spout. Use an Allen wrench or appropriate screwdriver based on the type of screw.
• Score the sealant around the spout with a utility knife.
• Pull the spout from the wall with both hands.

When removing a threaded spout:

• Use a utility knife to score the sealant around it.
• Use two hands to unscrew the spout counterclockwise until it is free.
• If you can’t get it to unscrew by hand, you may need to use locking pliers or a pipe wrench to help.

Tip: If you use a tool to help unscrew the spout, place a rag or duct tape between the spout and the jaws of the tool to keep from scratching the spout. (If you plan to recycle or dispose of the old spout, this may not be needed.)

Make sure your replacement faucet will match your original fittings.

If you have a threaded spout:

• Wrap fresh plumber's tape or thread-seal tape over the threading of the wall pipe.
• Put the new spout in place and turn it clockwise with your hands until it's secure.
• If you need to use an adjustable wrench or a pair of pliers to tighten it, use a rag or duct tape to protect the finish (and remove when the spout is tightened).
• Make sure the spout is pointing straight down into the tub.

If you have a slip-on spout:

• Slide it onto the pipe until the base meets the wall.
• Make sure it's facing directly downward.
• Insert and tighten the set screw to secure the spout in place.

For both types of spouts:

• Apply sealant designed for bathroom use where the base of the spout meets the wall.
• When all the new fittings are in place, turn the water supply to your house back on.
• Test the faucet and check for any leaks.

Tip: If you added new caulk or sealant, make sure it has dried to manufacturer's specifications before running water in the tub.

Removing bathtub faucet handles is essentially the same whether you have a one- or two-handled design.

• Begin by using a flat-head screwdriver to pry off the handle’s plastic cover (also called the plastic insert or index).
• Unscrew the handle screw with a flathead or Phillips-head screwdriver as needed.
• Wiggle the handle and pull it off. You may need a faucet handle puller if the handle will not come off by hand.
• If needed, place a shower socket wrench over the bathtub faucet stem until it covers the hex nut. Turn the wrench counterclockwise to loosen the nut until you can pull the stem free.
• Repeat the steps if you have a two-handled system.

Bathtub cartridges regulate water flow and temperature.
You generally only need to replace it if there’s a problem with the faucet, for example there’s a leak or it has difficulty turning.

• To change a bathtub cartridge, begin by removing the handle as described in Step 1.
• Remove the screws holding the escutcheon plate in place and slide out the escutcheon.
• Remove the retaining clip that holds the cartridge in place with a screwdriver.
• Remove the cartridge with pliers. You may need a cartridge-pulling wrench, depending on your plumbing configuration.
• Check the O-rings and replace as needed. New O-rings will reduce the chance of leaks.
• Insert the new cartridge (or repaired old one) and slide in the retaining clip to hold it in place.
• Follow the steps to replace the handle.

• Make sure your replacement handles and stems match the old ones in size and configuration (for example, don’t try to replace a one-handled system with a two-handled one). You can confirm this by bringing the old ones with you to the store when you buy the new ones.
• Put the new stem in the hold and turn clockwise to tighten. After you’ve secured it by hand, tighten it with a socket wrench.
• Slide the new handle over the stem until it comes into contact with the wall.
• Tighten the screw to secure the handle to the stem.
• Snap the plastic cover back in place.
• Repeat the steps if you have a two-handled system.

Tip: If the handles aren’t watertight at the walls, use caulk to make a seal.