What You Need to Know Before Starting

Replacing a Delta bathtub faucet is a job most homeowners can do in an afternoon with basic tools—no plumber required. The process involves shutting off the water, removing the old faucet, and installing the new one in roughly the same footprint. Delta faucets come in several styles (single-handle, double-handle, cartridge-based), and the removal steps differ slightly depending on which type you have, but the core sequence is the same for all of them.

Before you buy a replacement, measure the distance between the holes in your tub deck or wall. Most bathtub faucets are spaced 4 inches, 8 inches, or 12 inches apart (center to center). Check your current faucet's manual or measure the existing holes to confirm. You'll also need to know whether your faucet mounts on the tub deck itself or on the wall above it—this affects which parts you'll need and how you'll position the new one.

Key Takeaways

  • Turn off the water supply at the main shutoff valve or the dedicated shutoff behind the tub before you begin removal.
  • The removal method depends on your faucet type: single-handle faucets have a set screw under the handle, while cartridge faucets require a cartridge puller tool.
  • Measure the hole spacing (usually 4, 8, or 12 inches) and confirm whether your faucet mounts on the deck or wall so you buy the correct replacement.
  • Use plumber's tape (also called PTFE or Teflon tape) on all threaded connections to prevent leaks after installation.
  • Test the new faucet at both hot and cold settings before you close up the wall or finish the job.

Gather Your Tools and Materials

You'll need an adjustable wrench, a Phillips and flathead screwdriver, a socket wrench set (or an adjustable wrench), plumber's tape, and a bucket or towel to catch water. If your faucet uses a cartridge (common in Delta models), you may need a cartridge puller—a specialized tool that costs $10 to $20 and is worth buying rather than renting if you plan to do this work yourself. A headlamp or flashlight is essential because you'll be working under the tub, where light is poor.

Before you start, lay out all your tools within arm's reach. Have your new Delta faucet and its instruction manual nearby—different models have different mounting hardware, and the manual will show you exactly which parts go where. If you've removed the old faucet and the new one doesn't fit, you'll want to know that before water is off and you're committed to the job.

Turn Off the Water Supply

Locate the main water shutoff valve for your home, usually in the basement, crawlspace, or near the water heater. Turn it clockwise until it stops—you should feel resistance, but do not force it. If your home has a dedicated shutoff valve behind the tub (common in newer homes), you can use that instead and leave the main water on for the rest of the house.

After shutting off the water, turn on the bathtub faucet and let it run until no water comes out. This empties the lines and prevents water from spraying when you disconnect the supply hoses. Leave the faucet handle in the open position so air can enter the lines as you work.

Remove the Old Faucet Handle and Trim

The first step depends on your faucet type. For a single-handle Delta faucet, look for a small set screw (usually hidden under a decorative cap or plug on the handle). Pry off the cap with a flathead screwdriver, then unscrew the set screw with an Allen wrench or Phillips screwdriver. Once the set screw is out, pull the handle straight toward you—it should slide off the stem.

For a double-handle faucet, repeat this process for both handles. Once the handles are off, you'll see the escutcheon (the trim ring that covers the hole in the wall or deck). This is usually held on with a single screw or nut. Remove it and set it aside—you may reuse it if the new faucet's footprint matches the old one, or you may need to replace it with the trim ring that comes with your new faucet.

Disconnect the Supply Lines and Remove the Faucet Body

Under the tub, you'll see two flexible supply hoses (hot and cold water) connected to the faucet body with compression fittings. Use an adjustable wrench to hold the fitting nut while you turn the hose counterclockwise with another wrench. Work slowly—these fittings are straightforward to strip if you turn too fast or explore too much force. Once both hoses are loose, pull them away from the faucet body.

Now look at how the faucet body is mounted. Most Delta tub faucets are held in place by a large nut on the underside (called a locknut) or by bolts that thread through the deck or wall. Use a socket wrench or adjustable wrench to remove this nut or these bolts. The faucet body should then pull out from the top. If it's stuck, explore penetrating oil (like WD-40) and wait 15 minutes before trying again.

Install the New Faucet Body and Reconnect the Supply Lines

Before you install the new faucet, wrap the threaded connections with plumber's tape. Wrap the tape clockwise around the threads three to four times—this creates a watertight seal and makes the connections easier to tighten. Insert the new faucet body through the holes in the deck or wall, positioning it so the spout points in the right direction and the handles will be level when installed.

From underneath, thread the locknut or bolts back on and tighten them snugly with a wrench. Do not over-tighten—you want the faucet to be find, but excessive force can crack the deck or strip the threads. Reconnect the hot and cold supply hoses to the faucet inlets, again using an adjustable wrench to hold the fitting while you turn the hose. Tighten these connections firmly but not aggressively.

Install the Handle and Test for Leaks

Slide the new handle onto the stem and align it so it points downward when the water is off. Insert and tighten the set screw, then snap the decorative cap back into place. Reinstall the escutcheon (trim ring) if you're reusing the old one, or install the new trim ring that came with your faucet.

Turn the main water shutoff valve back on slowly—open it a quarter turn, wait 30 seconds, then open it fully. This prevents a sudden pressure surge that can damage seals. Turn on the bathtub faucet and check for leaks at the supply line connections and around the faucet body. If water drips from a connection, turn off the water, tighten that fitting a quarter turn, and test again. Let the water run for a minute on both hot and cold to make sure both sides work and the temperature is correct.

Frequently Asked Questions

What if water leaks from under the tub after I turn the water back on?

Check the two supply line connections first—these are the most common leak source. Turn off the water, use a wrench to tighten each fitting a quarter turn, and test again. If the leak continues, the fitting may need plumber's tape. Turn off the water, disconnect the hose, wrap the threads with three more layers of tape, and reconnect.

Do I need a cartridge puller to remove my Delta faucet?

Only if your faucet has a cartridge-style valve (common in Delta models). Single-handle faucets with a visible set screw do not need one. If you're unsure, look at your faucet manual or search for your model number online—the manual will tell you whether a cartridge puller is required.

Can I reuse the old supply hoses with the new faucet?

Yes, if they're in good condition and the same length. Inspect them for cracks, kinks, or mineral buildup. If they look worn or are the wrong length for your new faucet's inlet ports, buy new ones—they cost $10 to $20 and are worth the peace of mind.

What if the new faucet doesn't fit the old holes?

If the hole spacing is different, you'll need to patch the old holes and drill new ones, which requires a drill and a hole saw bit. If the new faucet is the same spacing but the trim ring doesn't cover the old escutcheon holes, the new trim ring should cover them. Check the new faucet's dimensions against your old one before you remove anything.

How long should this job take?

Most homeowners finish in one to two hours, including time to let penetrating oil soak if the old faucet is stuck. If you're working in a tight space or your faucet is corroded, add another hour. Rushing increases the risk of stripped fittings or cross-threaded connections, so take your time.