What You Need to Do Before You Start

Replacing a shower arm and head is a job you can do yourself if you have basic plumbing tools and are comfortable working with pipe fittings. The shower arm is the pipe that comes out of the wall; the head is what screws onto the end of it. You will need to turn off the water, unscrew the old head, unscrew the arm from inside the wall, install a new arm, and screw on a new head. The whole job usually takes 30 minutes to an hour, depending on how stuck the old parts are.

Before you begin, locate your main water shut-off valve and turn it off completely. Open a faucet downstairs to release pressure in the pipes. You do not need to drain the entire system — just stop the flow. If you only want to replace the head and not the arm, you can skip the water shut-off; the head unscrews by hand or with a wrench, and no water will spill out once you turn it off.

Key Takeaways

  • Turn off the main water supply before you unscrew the shower arm from inside the wall, but you can replace just the head without shutting off water.
  • The shower arm screws into a fitting inside the wall called a drop ell; you will need a pipe wrench to hold the fitting steady while you unscrew the arm.
  • Wrap new thread seal tape (also called plumber's tape) around the threads of the new arm before screwing it in, to prevent leaks.
  • The shower head screws onto the arm by hand or with a wrench; do not overtighten it or you may crack the fitting.

Tools and Materials You Will Need

Gather these items before you start: a pipe wrench (adjustable wrench works in a pinch), thread seal tape (white plumber's tape, sold in any hardware store for a few dollars), a new shower arm (usually 1/2-inch diameter, 6 to 8 inches long), and a new shower head. You may also want a bucket or towel to catch any water that drips when you unscrew the old arm.

If you are replacing only the head, you need the new head and possibly a wrench — many heads unscrew by hand. If you are replacing the arm, buy one made of brass or stainless steel; they resist corrosion better than galvanized steel and last longer. The arm should match the diameter of your existing pipes, almost always 1/2 inch.

How to Remove the Old Shower Head

Stand in the shower and grip the shower head with your hand. Turn it counterclockwise. If it moves easily, keep turning until it comes off completely. If it is stuck, wrap a towel around it to improve your grip, or use an adjustable wrench to turn it. Do not use a pipe wrench on the head itself — the teeth will damage the finish.

Once the head is off, you will see the threads on the arm. Look at them to see if they are wrapped in old thread seal tape or plumber's putty. You do not need to remove this if you are only replacing the head. If you are replacing the arm as well, you will remove the entire arm in the next step.

How to Remove and Replace the Shower Arm

If the old arm is stuck or corroded, spray it with penetrating oil (like WD-40) and wait 15 minutes. This makes it easier to unscrew. Reach behind the wall or into the wall cavity if it is accessible, and locate the fitting that the arm screws into — this is called a drop ell or elbow. You need to hold this fitting steady with one wrench while you unscrew the arm with another wrench.

Place one pipe wrench on the drop ell (the part inside the wall) and another on the arm itself. Turn the arm wrench counterclockwise while holding the drop ell wrench steady. The arm should unscrew. If you cannot reach the fitting, you may need to remove drywall or tile around the arm to access it. Once the arm is out, clean any old tape or putty off the threads of the drop ell.

Take your new shower arm and wrap thread seal tape around the threads, starting near the base and wrapping clockwise three to four times. The tape should overlap slightly with each wrap. Screw the new arm into the drop ell by hand first, then use a wrench to tighten it. Do not overtighten — hand-tight plus a quarter turn with a wrench is usually enough. If you overtighten, you may crack the fitting or strip the threads.

How to Install the New Shower Head

Wrap thread seal tape around the threads on the end of the arm, the same way you did for the arm itself — three to four clockwise wraps. Screw the new head on by hand, turning clockwise. Once it is hand-tight, you can use a wrench to snug it another quarter turn, but do not force it. The head should point straight down or at a slight angle, depending on your preference.

Turn the water back on at the main shut-off valve. Let the water run for a few seconds to clear air from the pipes. Check the connection where the arm meets the wall and where the head meets the arm. If water drips from either joint, turn off the water, unscrew the leaking part, add another wrap of thread seal tape, and screw it back on.

What to Do If the Old Arm Is Stuck or Broken

If the arm will not unscrew after you have sprayed it with penetrating oil and waited, you may need to cut it off. Use a hacksaw or reciprocating saw to cut the arm as close to the wall as possible. Once the arm is cut, the remaining piece inside the wall should unscrew more easily. If it still will not budge, you may need to remove the drop ell itself and replace it along with the arm — this requires more work and may mean cutting into the wall.

If the arm breaks while you are unscrewing it, leaving a piece stuck in the fitting, use a screw extractor or call a plumber. Trying to force it out can damage the fitting beyond repair. A plumber can remove the broken piece and install a new fitting if needed.

Common Mistakes to Avoid

Do not use plumber's putty on the threads — use only thread seal tape. Putty is for sealing around the base of the head where it meets the wall, not for the threaded connections. Do not overtighten the arm or head; you will crack the fitting or strip the threads, and then you will have a much bigger job. Do not forget to wrap the new arm with thread seal tape before screwing it in — this is what stops leaks.

Do not use a pipe wrench on the shower head itself; use only a regular wrench or your hand. The teeth on a pipe wrench will scratch and damage the head's finish. If water leaks from the joint after you have installed everything, do not ignore it — turn off the water, unscrew the leaking part, and add more tape or tighten it slightly.

Frequently Asked Questions

Can I replace just the shower head without turning off the water?

Yes. The head unscrews by hand or with a wrench, and once it is off, no water will flow out because the arm is sealed. You only need to turn off the main water supply if you are removing the arm itself from inside the wall.

What size shower arm do I need?

Most residential shower arms are 1/2 inch in diameter. Measure the diameter of your existing pipes or bring a photo to the hardware store and ask. The length is usually 6 to 8 inches, but this varies depending on how far your wall is from the fitting inside. Measure from the wall surface to where the old arm ended.

Why is my new shower head leaking?

The most common cause is not enough thread seal tape on the arm or head threads. Turn off the water, unscrew the head, add two more wraps of tape, and screw it back on. If it still leaks, the fitting itself may be damaged and need replacement.

Do I need a plumber for this job?

If the old arm unscrews easily and you have a pipe wrench, you can do it yourself. If the arm is severely corroded, broken, or you cannot access the fitting inside the wall, a plumber will save you time and frustration. The cost is usually $150 to $300 for labor plus parts.