Bathroom Tub Faucet Dripping: How to Find and Fix the Leak

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A bathroom tub faucet dripping from the spout is usually caused by a worn washer, a failed cartridge, or a damaged valve seat. In most cases you can stop the drip in an afternoon with basic hand tools, a few replacement parts, and a clear plan. This guide walks through diagnosing the source, shutting off the water, repairing the most common faucet types, and checking your work so the leak doesn’t come back.

Why a Tub Faucet Drips in the First Place

A tub faucet has a simple job: it opens and closes a path for water, and a seal or cartridge stops the flow when the handle is off. Over years of use, those seals harden, crack, or wear down, and a small amount of water slips past. Mineral deposits from hard water make the problem worse by scoring surfaces and blocking the tight fit that a seal needs.

The most common causes are:

• Worn rubber washers on compression faucets, the older two-handle style with a stem that screws in and out.
• A failed cartridge in single-handle and many newer two-handle faucets, usually a plastic or brass insert that controls flow and temperature.
• Corroded or pitted valve seats, the brass or metal rings the washer or cartridge seals against.
• Worn O-rings on cartridge or ball-type faucets, often the reason for a slow leak at the base of the handle rather than the spout.
• A loose or damaged stem, which can let water weep even when the handle is fully closed.

Knowing which part is failing tells you what to buy and how deep the repair goes. Before you take anything apart, figure out which faucet type you have.

Step 1: Identify Your Faucet Type

Tub faucets generally fall into four families, and the repair method depends on which one you own. Look at the handles and the spout. If you see two separate handles that you turn several times to open, you likely have a compression faucet. If you see one lever or a single handle that tilts side to side, you have a cartridge or ball faucet. Some two-handle faucets use cartridges instead of washers, so check both handles.

Faucet type	How it works	Typical leak source
Compression (two handles)	Rubber washer presses onto a valve seat	Worn washer or seat
Cartridge (one or two handles)	Single insert controls flow and mixing	Failed cartridge or O-rings
Ball (single lever)	Rotating ball with spring-loaded seats	Worn seats, springs, or O-rings
Disc (ceramic)	Two ceramic discs slide over each other	Debris or cracked disc

If you can’t tell, remove a handle cap and look inside. A stem with a rubber washer on the bottom suggests compression. A cylindrical part with an O-ring around it suggests a cartridge.

Step 2: Shut Off the Water Safely

Never work on a faucet with the water on. Start by closing the shutoff valves under the tub or behind an access panel, usually labeled hot and cold. If the tub has no individual valves, turn off the main water supply to the house and open the faucet briefly to relieve pressure. Place a towel in the drain to keep small parts from falling in, and put a rag over the tub floor to protect the finish.

Check that the water has stopped by turning the handles on. If water still comes out, the shutoff valves are either closed too little or not working. In that case, stop and call a licensed plumber, because a faulty valve can flood the wall cavity.

Step 3: Gather Tools and Replacement Parts

Most tub faucet repairs need only a short list of items. Gather them before you start so you don’t have to stop partway through.

• Flathead screwdriver and Phillips screwdriver
• Adjustable wrench or slip-joint pliers
• Allen wrench set (for set screws on many single-handle faucets)
• Penetrating oil for stubborn fasteners
• Plumber’s grease (silicone-based, safe for potable water)
• Replacement washers, O-rings, or cartridge matched to your faucet brand and model
• A valve seat wrench or seat dresser if the seat is damaged
• Old towel and a small container for screws

Take the old part to the store or photograph the markings on it. Many faucet makers have model-specific cartridges, and a generic part that looks similar may not seal correctly.

Step 4: Repair a Compression Faucet

Remove the Handle and Stem

Pry off the decorative cap on top of the handle to reveal the screw. Remove the screw, lift the handle off, and unscrew the packing nut with an adjustable wrench. Pull out the stem. Keep the parts in order so you can reassemble them correctly.

Replace the Washer and Check the Seat

Remove the brass screw at the bottom of the stem and swap the rubber washer for a new one of the same size and shape. Inspect the valve seat inside the faucet body. If it’s pitted or rough, use a seat wrench to remove it and install a new one, or use a seat dresser to smooth it. A smooth seat is what lets the new washer seal.

Reassemble and Test

Put a thin coat of plumber’s grease on the stem threads and O-ring, reinstall the stem, handle, and cap, then open the shutoff valves slowly. Turn the handle on and off a few times to check for leaks.

Step 5: Repair a Cartridge or Ball Faucet

Access the Cartridge

On a single-handle faucet, remove the decorative cap, loosen the set screw (often under the handle), and lift the handle off. Remove the retaining clip or nut that holds the cartridge in place. Pull the cartridge straight up, using pliers wrapped in tape to avoid scratching the finish if it sticks.

Replace the Cartridge or O-Rings

If the cartridge is worn, replace the whole unit with a matching model. Many faucets also have O-rings and a spring-loaded seat cup that can be replaced individually. Rub the new O-rings with silicone grease, and check that the cartridge orientation matches the old one. Most cartridges have a tab or index mark that must line up with the faucet body.

Clean the Body and Reassemble

Flush the cartridge housing with clean water to remove sediment. Reinstall the cartridge, clip or nut, handle, and set screw, then restore water and test in both hot and cold positions.

Step 6: Test and Confirm the Fix

Turn the water back on at the shutoff valves and run the faucet for a minute to clear air and debris. Close the handle fully and wait at least 10 minutes. If the spout stays dry, the repair worked. Check the base of the handle and the tub floor for moisture too, because a leak there can point to a different problem.

If the drip continues, return to the diagnosis. A common reason is a seat that wasn’t smoothed or a cartridge installed slightly out of alignment.

Common Mistakes to Avoid

• Forcing a stuck part. Use penetrating oil and gentle, steady pressure. Excess force can crack a valve body.
• Mixing up hot and cold. Mark the handles or the parts before you disassemble.
• Using the wrong washer or cartridge. Compression washers vary by size, and cartridges are model-specific.
• Skipping the seat inspection. A new washer won’t seal against a pitted seat.
• Over-tightening. Snug is enough. Crushing a washer or cracking a plastic cartridge creates a new leak.
• Using petroleum-based lubricant. It can degrade rubber parts. Stick with silicone-based grease.

Tips for Preventing Future Drips

• Clean aerators and screens every few months to remove mineral buildup.
• Avoid cranking the handle fully closed with force; a light close is enough.
• In hard-water areas, consider a water softener or periodic descaling of the faucet body.
• Replace washers or cartridges as part of routine maintenance once a faucet is more than several years old.

Recommended gear

A few inexpensive supplies make faucet repairs far easier and help prevent leaks from returning. Choose items labeled for potable water use.

• Silicone plumber’s grease, which lubricates O-rings and stems without breaking down rubber. View on Amazon
• Penetrating oil, useful for loosening corroded packing nuts and set screws. View on Amazon
• Faucet valve seat wrench set, which removes and installs brass seats without damaging them. View on Amazon
• Replacement O-ring and washer assortment, so you have common sizes on hand when a leak appears. View on Amazon

FAQ

Why does my tub faucet drip only when it’s turned off?

That’s the classic sign of a worn washer, cartridge, or valve seat. The seal isn’t closing fully, so water passes when the handle is in the off position.

Can I fix a dripping tub faucet without turning off the main water?

Often yes, if the tub has its own shutoff valves. If it doesn’t, you’ll need to shut off the main supply, so plan the repair for a time when you can go without water for an hour or two.

How long does a tub faucet repair usually take?

For a first-time DIYer working on a compression or cartridge faucet, expect roughly one to two hours including shutoff, disassembly, parts replacement, and testing.

Do I need to replace the whole faucet?

Usually not. Washers, cartridges, and seats are replaceable. Replacing the whole faucet makes sense if the body is cracked, corroded beyond repair, or the model is discontinued and parts are unavailable.

Why does my faucet still drip after I replaced the washer?

The valve seat is the most likely cause. If it’s pitted or rough, a new washer can’t seal properly. Inspect and smooth or replace the seat.

Is a dripping tub faucet a waste of water?

Yes. A steady drip can waste a significant amount of water over a month, and it can also raise your water bill and stain the tub. Fixing it promptly is worth the effort.

When should I call a plumber?

Call a licensed plumber if the shutoff valves won’t close, if the leak is inside the wall, if you see water damage or mold, or if the faucet body is cracked. A professional can also help if you’re unsure which parts fit your model.

Conclusion

A dripping tub faucet is almost always a worn washer, cartridge, or seat, and most fixes are within reach of a patient homeowner. Identify your faucet type, shut off the water, replace the failing part with a matched replacement, and test carefully. Taking the time to inspect the valve seat and avoid over-tightening will keep the repair lasting for years.

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