Allen wrench set
Use it for: Many slip-on tub spouts use a small set screw on the underside.
Shop Allen wrench setsBathroom plumbing
How to Replace a Bathtub Diverter Spout
To replace a bathtub diverter spout, first confirm the spout itself is the problem, then remove the old spout, match the connection type, install the new spout, and test both tub flow and shower diversion for leaks.
This is usually a manageable homeowner repair if the pipe stub-out is solid and accessible. The biggest mistake is buying the wrong style of spout or forcing the old one off the wrong way.
Before you start: Match the replacement spout to your pipe connection style and spout length before ordering. Some spouts thread on, while others use a set screw underneath.
Safety first
- Use a towel in the tub so dropped tools do not chip the finish.
- Cut old caulk carefully and keep the blade shallow near finished surfaces.
- Do not force a spout if you are not sure whether it is threaded or held by a set screw.
- Stop if the pipe stub-out moves in the wall, since that can turn a simple repair into an in-wall plumbing repair.
Tools you may need
Adjustable wrench
Use it for: Helps loosen or snug a threaded spout without needing a full wrench set.
Shop adjustable wrenches
Tongue and groove pliers
Use it for: Useful for turning a stubborn threaded spout with a rag protecting the finish.
Shop tongue-and-groove pliers
Rag or microfiber cloth
Use it for: Protects the finish and helps clean the pipe and wall area before installation.
Shop microfiber cloths
Plumber's tape
Use it for: Used on threaded pipe connections when the new spout instructions call for it.
Shop plumber's tape
Tub and tile caulk
Use it for: Seals the gap at the wall if the old seal was cut away or damaged.
Shop tub and tile caulkAs an Amazon Associate I earn from qualifying purchases. Repair Riot may earn a commission at no extra cost to you.
Step-by-step fix
Step 1: Make sure the diverter spout is really the problem
- Look for the usual signs of a failed diverter spout: water keeps running from the tub spout when the shower is on, the diverter knob is loose or sticky, or the spout drips heavily after use.
- Check that the leak or poor diversion is happening at the spout itself, not from the wall behind the spout or from the shower arm above.
- Grab the spout and gently wiggle it. A little movement can mean the spout is loose, but a lot of movement can point to a damaged pipe connection inside the wall.
- Take a photo and measure the spout length and the distance from the finished wall to the end of the pipe if you can see it. This helps you buy the right replacement.
If it works: You have confirmed the bathtub diverter spout is the likely failed part and you know what style and size to match.
If it doesn’t: If the problem is water leaking from inside the wall, from the valve area, or from a cracked pipe stub-out, this is not just a spout replacement.
Stop if:
- Water is staining the wall or ceiling below the tub area.
- The pipe coming out of the wall feels loose, bent, or damaged.
- You cannot tell whether the spout is threaded or slip-on and forcing it may damage the pipe.
Step 2: Set up the area and remove the old caulk line
- Turn off the tub faucet handles so no one starts the water while you are working. You usually do not need to shut off the home's water for this repair, but do not work with the faucet running.
- Put a towel in the tub to protect the finish and catch small screws or tools.
- If there is a bead of caulk where the spout meets the wall, score it carefully with a utility knife so the spout can come off cleanly without tearing the wall surface.
- Wipe away soap film and mineral buildup so you can clearly see the underside of the spout and the wall connection.
If it works: The work area is protected, the spout base is exposed, and the old caulk is no longer holding the spout in place.
If it doesn’t: If the caulk is thick and stubborn, cut it in a few light passes instead of one deep pass to avoid scratching the tub or wall.
Stop if:
- The wall surface is soft, crumbling, or wet behind the caulk line.
Step 3: Remove the old bathtub diverter spout the right way
- Look underneath the spout near the wall for a small set screw. If you find one, loosen it with the correct Allen wrench and pull the spout straight off the copper pipe.
- If there is no set screw, the spout is often threaded. Wrap the spout with a rag to protect the finish, then turn it counterclockwise by hand or with pliers over the rag.
- Work slowly. If the spout resists, double-check for a hidden set screw before applying more force.
- Once the spout is off, inspect the pipe stub-out for corrosion, damage, or leftover debris from the old connection.
If it works: The old spout is removed without twisting or damaging the pipe coming out of the wall.
If it doesn’t: If the spout will not budge, stop and confirm the connection style again. A stuck threaded spout can sometimes be worked loose with steady pressure, but forcing the wrong type can break the pipe.
Stop if:
- The pipe starts turning in the wall.
- The copper pipe kinks, cracks, or pulls outward.
- The threaded nipple is badly corroded or breaks loose in the wall.
Step 4: Match and prepare the new spout
- Compare the new spout to the old one. Make sure the connection style matches: slip-on to slip-on, or threaded to threaded.
- Check that the new spout will fit the pipe length you have. Do not assume all tub spouts fit the same stub-out length.
- For a threaded connection, clean the pipe threads and apply plumber's tape only if the new spout instructions call for it.
- For a slip-on connection, clean the copper pipe so the inside seal can slide on smoothly and seal properly.
- Dry-fit the new spout first so you know it will sit straight and close to the wall before final tightening.
If it works: The replacement spout matches the pipe connection and is ready to install without guesswork.
If it doesn’t: If the new spout does not match the old connection type or will not seat correctly at the wall, exchange it for the correct style before continuing.
Stop if:
- The pipe size or connection style does not match the new spout.
- The wall opening is damaged enough that the spout cannot sit flat against the finished surface.
Step 5: Install the new bathtub diverter spout
- For a threaded spout, hand-thread it onto the pipe and keep it straight so you do not cross-thread it. Tighten until it is snug and the spout faces downward correctly.
- For a slip-on spout, slide it fully onto the pipe until it meets the wall, then tighten the set screw firmly but do not overtighten and crush the pipe.
- If there is a visible gap at the wall, make sure the spout is fully seated and aligned before sealing anything.
- Apply a neat bead of tub and tile caulk around the top and sides of the spout where it meets the wall if needed, leaving the bottom unsealed so any hidden leak can show itself instead of staying trapped.
If it works: The new spout is secure, straight, and seated properly at the wall.
If it doesn’t: If the spout will not align correctly or keeps backing off before it points down, remove it and recheck the fit and connection style rather than forcing it.
Stop if:
- The spout cannot be tightened securely without the pipe moving in the wall.
- Water starts leaking from the wall opening during installation or testing.
Step 6: Test the repair in real use
- Run tub water first and watch the spout base, underside, and wall connection for drips.
- Pull or lift the diverter and switch to shower mode. Check that most of the water now goes to the shower head and only minimal residual water comes from the tub spout.
- Let it run for a few minutes, then turn the water off and watch for delayed dripping from the spout connection at the wall.
- Wipe the area dry and check again after the next normal bath or shower to make sure the repair holds under regular use.
If it works: The spout stays dry at the wall, the diverter works smoothly, and the shower diverts properly without an ongoing leak.
If it doesn’t: If water still pours from the tub spout during shower use or leaks from the wall area, the issue may be the wrong spout, a poor fit, or a problem farther back at the valve or pipe connection.
Stop if:
- Water leaks from inside the wall opening.
- The diverter still does not work correctly with a properly matched new spout.
- The pipe connection loosens after testing.
Replacement Parts
Find a bathtub diverter spout on Amazon
Match the replacement spout to your pipe connection style and spout length before ordering. Some spouts thread on, while others use a set screw underneath.
As an Amazon Associate I earn from qualifying purchases. Repair Riot may earn a commission at no extra cost to you.
Verify the repair
- Tub water runs from the spout without leaking at the wall.
- The diverter engages and sends water to the shower properly.
- Only minor brief drips come from the spout after switching to shower mode, not a steady stream.
- The spout feels solid and does not wiggle during normal use.
- The area around the wall opening stays dry after the next full shower or bath.
FAQ
How do I know if my tub spout is threaded or slip-on?
A slip-on spout usually has a small set screw on the underside near the wall. A threaded spout usually has no set screw and unscrews by turning counterclockwise. Check carefully before applying force.
Do I need to shut off the house water to replace a bathtub diverter spout?
Usually no, because you are replacing the spout at the end of the tub outlet, not opening a pressurized supply line. Just make sure the faucet is off and no one turns it on while you are working.
Why does some water still come out of the tub spout when the shower is on?
A small amount can be normal on some setups. A strong steady flow usually means the diverter is worn, the new spout is not the right fit, or the problem is actually at the tub-shower valve.
Should I caulk all the way around the tub spout?
It is better to seal the top and sides and leave the bottom open. That way, if water ever gets behind the spout, it can show itself instead of staying trapped in the wall.
What if the pipe coming out of the wall moves when I try to remove the spout?
Stop there. A moving stub-out can mean the pipe is loose or damaged inside the wall, and continuing can break the connection and cause a hidden leak.