How to Replace a Bathtub Faucet

Plumbing repairs are daunting for a lot of DIYers, but a bathtub faucet replacement is a quick and easy job that just about any homeowner can tackle with minimal tools and experience. In this step-by-step guide, we’ll explain how to replace a bathtub faucet yourself to give your bathtub and shower a fresh new look with little time and money invested.

Quick Takeaways

• The most important step is buying the right type of bathtub faucet. If you end up with the wrong one, the job becomes more complicated and will require help from a plumber.

• If you’re making changes to the type of faucet you have, including relocating it, you should call a professional for help.

• Always make sure to shut the water off at your water main and drain the fixture before you start working on it.

Materials for a Bathtub Faucet Replacement

Here’s what you’ll need to replace your bathroom faucet:

• Screwdriver

• Utility knife or razor blade

• Plumber’s tape (if you have a screw-on faucet)

• Plumber’s grease (if you have a slip-on faucet)

• Rubbing alcohol

• Cleaning towel

• Silicone caulk

• New faucet

1. Choosing the Right Type of Bathtub Faucet

The most crucial part of the entire process is making sure you purchase the right type of faucet for your bathtub. Here’s how to do so.

First, check to see if you have a screw-on or slip-on bathtub faucet. Look or feel around the outside of the old faucet for a small screw. This may sound counterintuitive, but if you find a screw, it means you have a slip-on bathtub faucet. If there’s no screw, you have a screw-on bathtub faucet. Either way, you’ll need to buy the same type. 

Next, you’ll actually need to take your current faucet off, so refer to steps 2 through 4 to do this properly.

Both slip-on and screw-on bathtub faucets can use a plumbing connection that’s either about 1 inch from the wall or 4 inches from the wall. Remove the faucet and check how far the copper pipe extends from the wall. Make sure you buy a new faucet that will fit over the copper pipe and sit flush with the wall once connected. 

Finally, look to see if your bathtub faucet has a diverter. This is usually a small plunger on the faucet itself that directs the water up to your showerhead. If your old faucet has a diverter, buy a new faucet that has one as well. If you have a separate diverter installed on the wall, buy a faucet without a diverter. You may want to consider replacing the bathtub diverter, too, so that the new pieces match.

2. Shut the Water Off

Start your bathtub faucet replacement by shutting off your water supply. You can do this by heading to your water main and closing the shutoff valve.

Test that your water is off by turning your bathtub faucet on and letting it drain for about 30 seconds. If the water continues to flow, double-check that the water main is shut. 

If the water still continues to flow but the main is shut, call a plumber to help you diagnose the issue. It’s possible that your main water valve isn’t holding, which will require a replacement.

3. Score the Caulking Around Your Bathtub Faucet

Use a utility knife or razor blade to score the caulking between the bathtub faucet and the wall to break the seal. Be careful not to scratch the tile or stone behind the faucet.

4. Remove the Faucet

Next, you can remove the old faucet. If you have a screw-on bathtub faucet, rotate it until it comes loose. If you have a slip-on faucet, unscrew the set screw with a flathead screwdriver or a hex screwdriver, and then gently pull the faucet off of the copper pipe.

5. Clean the Pipe Connection and Caulk the Opening in the Wall

If you’re working with a screw-on bathtub faucet, remove the plumber’s tape from the threads on the copper pipe and clean the copper with some rubbing alcohol and a rag. If you have a slip-on bathtub faucet, you can just clean off any plumber’s grease and debris using rubbing alcohol and a rag.

Once the copper pipe is clean, apply some silicone caulk around the pipe to seal off the opening in the wall around the connection.

6. Waterproof the Pipe

Now you’re ready to prepare the pipe for your new faucet. If you have a slip-on faucet, apply a thin coat of waterproof plumber’s grease to the copper. For screw-on bathtub faucet connections, wrap pipe thread tape around the copper threads. Stretch the tape slightly as you wrap the threads, and aim for two to three layers of tape. Smooth the tape over the threads with your fingers.

7. Install the New Bathtub Faucet

Next, screw or slip on your new bathtub faucet. For screw-on faucets, be sure not to overtighten, rotating the faucet just until it sits flush with the wall with the spout facing downward.

For slip-on faucets, simply slip the new plumbing fixture over the copper pipe until it sits flush with the wall. Then, screw in the set screw and test to make sure the faucet is secure.

8. Caulk Around the New Faucet

Apply a bead of silicone caulk around the bathroom faucet where it meets the wall, but only apply to the top and sides. Leave a small gap at the bottom to allow any internal water and moisture to escape. 

Use your finger to smooth out the caulk, and wipe away any excess with a rag.

9. Turn Your Water on and Check for Leaks

Finally, you can turn your water back on at the water main and check for any leaks. Let the cold and hot water run for a full minute with the diverter engaged and then another minute with the diverter disengaged. 

If you notice water dripping from behind the faucet, call in a plumber for help. If the faucet is leak-free, you can call this a successful DIY bathtub faucet replacement.

When to Hire a Professional for Bathtub Faucet Replacement

Replacing a bathtub faucet is a simple and straightforward repair most of the time, but there are some cases where the job requires help from a professional. Call in a plumber if:

• You’re switching the type of bathtub filler you have: If you fell in love with a particular faucet but it’s not the same kind (for example, it’s a slip-on faucet, and your old one is a screw-on faucet), you should call a plumber for help. They can remove the old copper connection and install the appropriate one. At that point, it’s more cost-effective just to have the professional install the new faucet, too.

• You want to change where the faucet is mounted: If you have a deck-mounted faucet and want a floor-mounted/freestanding or wall-mounted faucet instead (or vice versa), a plumber can reroute the water lines to make the installation possible. Again, just have your pro install the new tub spout, too, as there likely won’t be much of an additional cost.

• You’re relocating the bathtub faucet: When moving a faucet to the opposite side of the tub for better accessibility or based on your bathroom layout, call in a certified plumber. They can install new plumbing lines behind the wall to make the new connection. This is usually part of a bathroom remodel anyway, so you’ll likely already have a plumber on-site.

• You notice leaks before, during, or after the replacement: If your bathtub faucet is leaking before the replacement, there’s a chance that installing a new one will fix the problem. However, it’s not guaranteed, so it’s best to call in a pro. If the faucet is leaking after the replacement or shutting your water main doesn’t stop water flowing from the faucet during the replacement, defer to an expert for help. Even if you know how to fix a leaky bathtub faucet, a professional can guarantee a permanent solution that avoids major water damage and mold growth down the road.

• You’re installing a custom bathtub faucet: Most faucet brands have universal fittings, so if you’re going with something made by Delta, Moen, Kohler, Pfister, or another common plumbing fixture brand, you should be able to handle the work yourself. If you’re installing a custom fitting, you’ll likely need a plumber to tackle the job for you.

FAQ: Bathtub Faucet Replacement

Yes, you can absolutely replace just the tub faucet in your bathroom. Provided you buy the same type of bathtub spout, this is a relatively simple DIY project that you can get done in under an hour. If you’re replacing your bathtub faucet spout due to a leak, though, have a professional complete the job for you to ensure you don’t have ongoing issues.

Replacing a bathtub faucet will cost you an average of between $250 and $350, which includes $100 to $200 for the fixture itself and around $150 for the labor. The labor cost is a minimum that most plumbers charge as a trip fee, as the actual work will take less than an hour in most cases.

A dripping bathtub faucet is usually caused by corrosion or damage on the O-rings inside your faucet. To replace them, shut the water off at your water main, remove the faucet, and replace the rubber O-rings before reinstalling. If you need to fix a leaky bathtub faucet with two handles, you’ll usually have three O-rings — one on each faucet handle and one on the faucet itself. A single-handle faucet usually only has two. In either case, it may be easier, although more expensive, to replace the entire shower faucet and bathtub faucet handles, which will include new O-rings as stock replacement parts.

Unfortunately, no, not all bathtub faucets are interchangeable, and you need to make sure you buy the right kind before replacing yours. There are three things to pay attention to. First, check to see if yours is a slip-on or screw-on faucet. Second, check how far out the copper plumbing connection extends from the wall behind the bath — most faucets connect about an inch out or four inches out, and the two types aren’t interchangeable. Finally, faucets with built-in diverters to divert water to the shower head aren’t interchangeable with those that use a separate diverter.