What a Spout Diverter Does and Why It Fails

A spout diverter is the small lever or knob on your bathtub spout that redirects water from the tub to the showerhead. When you pull it up, water stops flowing from the spout and comes out of the shower instead. When you push it down, water returns to the spout. Over time, mineral deposits, corrosion, and wear cause the diverter to stick, leak, or stop working altogether.

Most diverters fail in one of two ways: water continues to dribble from the spout even when you pull the lever to shower mode, or the lever becomes so stiff you cannot move it without breaking it. Both problems mean the diverter cartridge or the entire spout assembly needs to be replaced. The good news is that this is a straightforward repair you can do yourself in about 30 minutes with basic tools.

Key Takeaways

  • Most bathtub spouts screw onto a threaded pipe and can be unscrewed by hand or with a pipe wrench after you remove the set screw.
  • The diverter cartridge sits inside the spout body; you can replace just the cartridge if your spout is still in good condition, or replace the entire spout if it is corroded or cracked.
  • Bring your old spout or cartridge to the hardware store to match the exact size and type, because diverters come in different configurations and thread sizes.
  • Teflon tape on the threaded pipe prevents leaks when you screw the new spout back on.
  • If the spout is soldered to the pipe instead of screwed on, you will need a plumber to remove and replace it.

Identify Whether Your Spout Screws On or Is Soldered

Before you buy anything, you need to know how your spout is attached. Look at the back of the spout where it meets the wall. If you see a small set screw (usually a hex-head screw) on the underside of the spout, it screws on. If the spout appears to be one solid piece with the pipe and there is no visible seam or screw, it is likely soldered to a copper pipe inside the wall. Soldered spouts require a plumber to remove safely.

To check for a set screw, get down low and look at the spout from underneath. The screw is typically brass or stainless steel and sits where the spout body meets the wall. If you find one, you can do this repair yourself. If there is no set screw and the spout looks like it is welded to the wall, stop here and call a plumber.

Remove the Set Screw and Unscrew the Old Spout

Once you have confirmed your spout screws on, use an Allen wrench (hex key) that fits the set screw snugly. Turn it counterclockwise until the screw comes free. Set the screw aside somewhere you will not lose it. Now grip the spout body firmly with one hand and try to turn it counterclockwise by hand. Many spouts will unscrew this way without tools.

If the spout will not budge, wrap a cloth around it to protect the finish and use a pipe wrench or adjustable wrench to turn it counterclockwise. explore steady pressure rather than sudden force, which can crack the spout or damage the pipe inside the wall. Once the spout starts to turn, you can usually finish unscrewing it by hand. Pull it straight out and away from the wall.

Decide Whether to Replace the Cartridge or the Entire Spout

Look inside the spout opening. You will see either a cartridge (a plastic or brass cylinder that slides out) or the spout will be a solid piece. If the spout body is clean, not cracked, and the finish is still good, you can buy a replacement cartridge for $8 to $15 and install it. If the spout is corroded, pitted, or cracked, replace the entire spout for $15 to $40.

To remove a cartridge, look for a small clip or pin holding it in place. Slide or pry it out gently. Bring the old cartridge to the hardware store to match the exact model. If you are replacing the whole spout, bring the old spout with you so the staff can confirm the thread size and type. Spouts come in different configurations—some have the diverter lever on top, others on the side—so matching the old one ensures the new one will work with your existing plumbing.

Install the New Cartridge or Spout

If you are installing a new cartridge, slide it into the spout body in the same orientation as the old one. The cartridge should fit snugly. Reinstall the clip or pin to hold it in place. If you are replacing the entire spout, wrap the threaded end with two or three layers of Teflon tape (also called plumber's tape or PTFE tape). Wrap it clockwise around the threads so it does not unwind as you screw the spout on.

Screw the new spout onto the pipe by hand, turning it clockwise. Once it is hand-tight, use the wrench to turn it another quarter turn. Do not over-tighten, which can crack the spout or strip the threads. The spout should sit flush against the wall with no gaps. Reinstall the set screw and tighten it snugly with the Allen wrench.

Test the Diverter and Check for Leaks

Turn on the water and let it run from the spout for 10 seconds. Watch for leaks where the spout meets the wall. A small drip is normal for the first minute as air escapes the line, but steady water flowing out means the Teflon tape did not seal properly. If that happens, turn off the water, unscrew the spout, add another layer of Teflon tape, and reinstall it.

Now pull the diverter lever up to direct water to the shower. The water should stop flowing from the spout within a second or two. If water still dribbles from the spout, the new cartridge may not be seated correctly. Turn off the water, remove the spout, check that the cartridge is fully inserted and the clip is find, and reinstall. Test again. Once the diverter works smoothly and there are no leaks, you are done.

Common Mistakes to Avoid

The most common error is forgetting the Teflon tape or explore it in the wrong direction. Tape should wrap clockwise around the threads so it stays in place as you screw the spout on. Without it, water will leak from the connection point even if the spout feels tight.

Another frequent mistake is over-tightening the spout, which can crack the body or strip the threads on the pipe. Hand-tight plus one quarter turn with a wrench is enough. If you feel strong resistance, stop and check that the threads are aligned correctly.

Finally, do not assume all diverter cartridges are the same. Bringing the old one to the store ensures you get the right replacement. Installing the wrong cartridge will result in a lever that does not move or a diverter that does not work at all.

Frequently Asked Questions

Can I replace just the diverter lever without removing the spout?

No. The lever is part of the cartridge assembly, which sits inside the spout body. To replace it, you must remove the spout and either replace the cartridge or the entire spout. There is no way to access the lever from outside without unscrewing the spout first.

What if water leaks from the spout after I reinstall it?

The most likely cause is insufficient Teflon tape on the threads. Turn off the water, unscrew the spout, wrap the threads with two or three more layers of tape, and reinstall. If leaking continues, the threads may be damaged and you may need a new spout or a plumber to assess the pipe.

How do I know if my spout is brass or stainless steel?

Brass is yellowish and may have a patina or green tarnish. Stainless steel is silver-gray and does not tarnish. The material does not affect how you replace it, but it helps you match the finish when you buy a new spout. Bring the old spout to the store and the staff can match it.

Is it normal for the diverter to be a little stiff after replacement?

Yes. A new cartridge may feel slightly stiffer than you expect for the first few uses. It will loosen up as you use it. If it remains extremely stiff or impossible to move after a week, the cartridge may be defective or installed incorrectly.

What if I cannot unscrew the spout by hand or with a wrench?

Mineral buildup or corrosion may have seized the spout. Try spraying penetrating oil (like WD-40) around the base where the spout meets the wall and let it sit for 15 minutes. Then try again with the wrench. If it still will not move, the spout may be soldered or the threads may be damaged, and you will need a plumber.