How to Fix a Dripping Bathtub Spout: Step-by-Step Guide

A dripping bathtub spout wastes thousands of gallons of water per year and often signals a worn cartridge or diverter that will only get worse. The fix is usually straightforward — either swap the spout itself or replace the cartridge inside the faucet body.

A dripping bathtub spout wastes thousands of gallons of water per year and often signals a worn cartridge or diverter that will only get worse. The fix is usually straightforward — either swap the spout itself or replace the cartridge inside the faucet body. Neither job requires a plumber, and most homeowners can complete the repair in under an hour.

This guide walks you through identifying the type of spout you have, removing and replacing it, and diagnosing whether the real problem is the cartridge inside the valve body.

What You Need

• Replacement tub spout (match your faucet brand and connection type) — Bring the old spout to the hardware store or note the brand and model to ensure a correct fit.
• Faucet cartridge puller set — Makes cartridge removal straightforward without damaging the valve body.
• Plumber’s silicone grease — Lubricates O-rings on the new cartridge or spout nipple for a watertight seal.
• Allen wrench set, adjustable wrench, flathead screwdriver, and needle-nose pliers

Step 1: Identify Your Spout Type and Drip Source

Before buying parts, determine two things: the connection type and whether the spout or the valve is causing the drip.

Connection type:

• Slip-on spout: Has a small Allen (hex) set screw on the underside near the wall. The spout slides over a copper pipe stub-out and is held by the screw.
• Threaded spout: No set screw. Threads directly onto a threaded nipple coming out of the wall.

Drip source:

• Drip when faucet is fully off: The valve cartridge or seat is worn. The spout itself is fine — replace the cartridge.
• Drip only from spout when shower is on: The diverter inside the spout has failed. Replace the spout.
• Water seeping around the wall where the spout meets the tile: The spout-to-wall seal has failed. Re-caulk the joint and possibly replace the spout.

Step 2: Remove the Existing Spout

For slip-on spouts:

1. Use an Allen wrench to loosen the set screw on the underside of the spout (counterclockwise). You do not need to remove it completely — just loosen until the spout slides freely.
2. Pull the spout straight out away from the wall. It should slide off the copper stub-out.
3. Inspect the stub-out for corrosion or damage. Wipe it clean.

For threaded spouts:

1. Insert a large screwdriver or a wood dowel into the spout opening to use as a turning handle.
2. Rotate the spout counterclockwise until it unthreads completely from the nipple.
3. If the spout is stuck, wrap the body in a cloth and use an adjustable pipe wrench. Do not apply force to the decorative trim ring.

Step 3: Install the New Spout

For slip-on spouts:

1. Apply a thin coat of plumber’s silicone grease to the copper stub-out. This helps the new spout slide on easily and creates a better O-ring seal.
2. Align the set screw hole on the underside of the new spout with the flat side or hole on the stub-out.
3. Slide the spout onto the stub-out until the back of the spout sits flush against the wall.
4. Tighten the set screw firmly with the Allen wrench — snug but not stripping.

For threaded spouts:

1. Wrap the nipple threads with two layers of plumber’s Teflon tape, going clockwise around the threads.
2. Thread the new spout on by hand, clockwise, until snug.
3. Tighten with a cloth-wrapped wrench until the spout aligns correctly (opening facing down). Do not back it off to align — overtighten slightly if needed to reach correct orientation.

Apply caulk to the wall joint: Run a thin bead of white silicone caulk around the back of the spout where it meets the tile. Smooth with a wet finger and allow to cure per the label before running water.

Step 4: Replace the Cartridge (If Valve Is the Problem)

If the drip persists after replacing the spout, or if water drips when the handles are fully off, the cartridge inside the faucet body needs replacement.

1. Shut off the water supply at the bathroom shutoff or main valve.
2. Remove the faucet handle. Pry off the decorative cap, remove the screw beneath it, and pull the handle off. Some handles require a handle puller if corrosion has seized them.
3. Remove the cartridge retaining clip (a U-shaped metal clip) with needle-nose pliers. Pull straight up to remove it.
4. Pull out the cartridge. Use a cartridge puller tool or grip the cartridge stem with pliers and pull straight out with steady force. Never twist — twisting can break the cartridge ears.
5. Bring the old cartridge to the hardware store to find an exact match, or note the brand/model on the faucet.
6. Lubricate the O-rings on the new cartridge with silicone grease.
7. Insert the new cartridge in the correct orientation (ears aligned with the slots in the valve body).
8. Reinstall the retaining clip, then the handle.
9. Turn the water back on and test both hot and cold positions for drips.

Preventing Future Drips

• Replace cartridges proactively every 8 to 10 years in homes with hard water, as mineral deposits accelerate O-ring wear.
• Avoid slamming faucet handles to the off position — this water hammer damages valve seats over time.
• Flush the aerator annually to prevent mineral buildup from increasing upstream pressure on valve seals.

Related Reading

• How to Fix a Leaky Faucet
• How to Fix a Bathroom Faucet Handle
• How to Replace a Shower Head