How to Replace a Shower Head and Arm in Your Bathroom

What You Need to Do Before You Start

Replacing a shower head and arm takes about 30 minutes to an hour and requires only basic tools you likely have at home. The job breaks into two parts: removing the old fixtures and installing the new ones. You do not need to turn off the water to your whole house — just close the valve on the shower line if one exists, or turn off water at the main if you cannot locate a shower valve. If you cannot find either, you can work with water on; just expect some dripping.

Before you buy a replacement arm, measure the distance from the wall to the center of your current shower head. This measurement tells you what length arm you need — common sizes are 6, 8, 10, and 12 inches. Take a photo of your current setup with your phone so you can match the finish (chrome, brushed nickel, matte black) when you shop. Bring the old arm with you to the store if possible, because thread sizes vary and the staff can confirm your new arm will screw into your existing fitting inside the wall.

Key Takeaways

Turn off the water at the shower valve or main before you start, or be ready for water to drip from the wall fitting when you unscrew the old arm.
Measure the distance from wall to shower head center to know what arm length to buy, and match the finish of your current fixtures.
Use an adjustable wrench on the fitting inside the wall while you turn the arm with your other wrench to avoid cracking the fitting.
Wrap new threads with plumber's tape before screwing in the new arm, and hand-tighten the shower head before using a wrench for the final quarter-turn.
Test for leaks at both connection points before you consider the job done.

Removing the Old Shower Head

Start by unscrewing the old shower head by hand. Most unscrew counterclockwise. If it is stuck, wrap a cloth around it to protect the finish and use an adjustable wrench or pipe wrench to turn it. Do not use a wrench on the arm itself — you need that arm to stay in place while you work. Once the head is off, you will see the threaded end of the arm sticking out of the wall.

Look inside the shower head opening to see if there is a rubber washer or O-ring. If there is, remove it and set it aside — you will need a new one for your replacement head. Most hardware stores sell washer kits for a few dollars, and having the right size prevents leaks later.

Removing the Old Arm

This is where most people run into trouble. The arm is screwed into a fitting that is hidden inside the wall, and if you turn the arm too hard without holding the fitting steady, you can crack the fitting and create a much bigger repair job. Use two wrenches: one on the fitting inside the wall (if you can reach it) and one on the arm itself. If the fitting is completely hidden, you may only be able to grip the arm. Turn slowly and steadily counterclockwise.

If the arm will not budge after a few minutes of steady turning, spray it with penetrating oil (like WD-40) and wait 15 minutes. Try again. Do not force it — a cracked fitting inside the wall means cutting into tile or drywall to repair it. Once the arm comes free, water may drip from the hole in the wall. This is normal. Have a towel ready.

Preparing and Installing the New Arm

Before you screw in the new arm, wrap the threaded end with plumber's tape (also called PTFE tape or Teflon tape). Wrap it clockwise around the threads three to four times, pulling it tight as you go. This tape seals the connection and prevents leaks. It costs a dollar or two and is essential — do not skip it.

Screw the new arm into the wall fitting by hand first, turning clockwise. Once it is hand-tight, use a wrench to turn it another quarter-turn. Do not over-tighten — you are looking for snug, not maximum force. The arm should point straight out from the wall or angle slightly downward toward the tub. If it is not at the right angle, unscrew it, reposition it, and tighten again. This is easier to do now than after the head is on.

Installing the New Shower Head

If your new shower head came with a washer or O-ring, slide it onto the threaded end of the arm now. Screw the head on by hand, turning clockwise, until it is snug. Then use a wrench to turn it another quarter-turn. Again, snug is the goal — over-tightening can crack the fitting inside the head or strip the threads.

Some shower heads have a collar or escutcheon (a trim ring) that hides the hole in the wall. If yours does, slide it up the arm before you screw on the head, then slide it down against the wall after the head is tight. This covers any gaps or old marks on the wall.

Testing for Leaks

Turn the water back on slowly. Watch the connection where the arm meets the wall and where the head screws onto the arm. A small drip in the first few seconds is normal as air escapes the line. If water continues to drip after 30 seconds, turn the water off and tighten the connection another quarter-turn with a wrench. Wait and check again.

If the leak is at the arm-to-wall connection and tightening does not stop it, you may need to unscrew the arm, add more plumber's tape, and reinstall it. If the leak is at the head itself and tightening does not help, check that the washer is seated properly or try a new washer. Let the shower run for a minute to confirm everything is dry, then you are done.

Common Mistakes to Avoid

The most common error is over-tightening, which can crack fittings or strip threads. A quarter-turn past hand-tight is enough. Another mistake is forgetting plumber's tape on the arm threads — this almost always causes a leak at the wall connection. Do not assume the fitting inside the wall is the right size for your new arm; confirm this at the store before you buy.

A third mistake is not holding the wall fitting steady while you remove the old arm. If you feel resistance that seems wrong — a grinding feeling rather than smooth turning — stop and do not force it. Spray with penetrating oil and wait longer. Forcing a stuck fitting is how you end up with a cracked fitting inside the wall and a much larger job ahead.

Frequently Asked Questions

Do I need to turn off the water to replace a shower head and arm?

You do not have to, but it is easier if you do. If your shower has a shut-off valve, close it. If not, close the main water valve. If you cannot find either, you can work with water on — just expect water to drip from the wall fitting when you unscrew the old arm. Have a towel and bucket ready.

What if the old arm is stuck and will not unscrew?

Spray the connection with penetrating oil and wait 15 to 30 minutes. Try again with steady, even pressure. Do not force it — a cracked fitting inside the wall is a much bigger repair. If it still will not move after two or three attempts, you may need a plumber.

Can I use the old shower head on the new arm?

Yes, if the old head is in good condition and the threads match. Unscrew it from the old arm, wrap plumber's tape on the new arm's threads, and screw the old head on. Test for leaks the same way.

What size arm do I need?

Measure from the wall to the center of your current shower head. This is your arm length. Common sizes are 6, 8, 10, and 12 inches. Bring this measurement and a photo of your current setup to the store, or bring the old arm itself so staff can confirm the thread size matches.

Why is water dripping from the wall after I removed the old arm?

The water line inside the wall is open. This is normal. Have a towel ready and screw the new arm in as quickly as you can. Once the new arm is installed, the dripping stops.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.