A dripping bathtub faucet looks like a small problem until you add up the water bill. A steady drip can waste nearly 700 gallons of water a year, and the repair usually costs between $10 and $25 in parts and takes 20 to 40 minutes. You do not need to replace the faucet: worn internal parts are almost always the culprit, and swapping a gasket, O-ring, cartridge, or valve seat restores the seal. The fix follows the same logic whether the faucet has one handle or two, once you identify the valve type inside. Understanding the differences between kitchen and bathroom faucet types helps you name what you are working on before you open anything.
Why Bathtub Faucets Leak
Every drip has a mechanical cause, and the list of suspects is short. Constant turning of the handles wears out gaskets, so water escapes around the handle. Rubber and plastic O-rings deteriorate with age and exposure, causing drips from the spout or the base. Valve seats develop mineral buildup that lets water past the seal. Occasionally the problem is not the faucet at all but the water pressure in the house running too high.
- Worn gasket around the handle from years of turning.
- Loose, cracked, or flattened O-rings.
- Corroded valve seat with mineral deposits.
- High or fluctuating water pressure.
The same wear shows up across the house, and fixing a leaking water heater follows the same pattern of diagnosing the failing component before replacing parts.
The Anatomy of a Faucet
Every bathtub faucet contains the same core parts: a handle, a stem or cartridge that opens and closes the water path, a packing nut that seals the stem, a valve seat where the stem meets the body, and the spout. Leaks happen when any one of those seals fails.
Knowing the names matters when you shop: hardware stores stock washer kits, O-ring assortments, and universal cartridges, and a clerk can match a part to a photo faster than to a description.
How to Tell Which Part Is Failing
Watch where the water comes from. A drip from the spout points to a worn washer or cartridge. Water collecting around the handle points to the packing nut or an O-ring. A drip that continues after the handle is closed points to the valve seat. Constant dripping at several fixtures at once points to pressure rather than parts.
Checking the Water Pressure First
Screw a pressure gauge onto a hose bib or the laundry connection and read the pressure with no fixtures running. Most homes operate between 40 and 80 psi; above that range, regulators and seals wear out faster, and the faucet repair may not hold until the pressure is corrected.
Faucet Types and What They Mean for the Repair
Bathtub faucets come in two broad families, and the repair differs mainly in which part you replace.
Two-Handle Compression Faucets
Older two-handle faucets use compression valves: turning the handle threads a stem down onto a rubber washer to stop the flow. When the washer wears, water slips past. The repair is replacing the washer, the seat, or both, and tightening the packing nut that seals the stem.
Single-Handle Cartridge Faucets
Single-handle faucets route hot and cold through a cartridge that slides or rotates to mix the temperature. When the cartridge’s seals fail, the faucet drips from the spout. Replacing the whole cartridge is faster than rebuilding individual seals and costs little more.
Pullout and Pull-Down Designs
Kitchen faucets with pullout spray heads fail at the hose connections and diverter, and the same shut-off, drain, and cartridge logic applies. A pullout faucet fix often starts with reseating the hose or replacing the spray head O-rings rather than the valve itself.
Identifying Your Valve Type Before Buying Parts
Look for a brand name and model number stamped on the faucet body or under the handle. Take that number, or the old part itself, to the hardware store, and buy the matching cartridge or washer kit. Guessing at the valve type is the most common way to end up with the wrong part and a second trip.
Repairing a Two-Handle Bathtub Faucet
Two-handle repairs take about 20 to 30 minutes once the water is off.
- Close the fixture shut-off valves under the sink or tub, or shut off the main.
- Remove the handle screw, usually hidden under a cap, and pull the handle free.
- Unscrew the stem with a stem wrench, turning counterclockwise.
- Replace the washer on the stem and the seat in the body if either is worn.
- Wrap the threads with plumber’s tape, reinstall the stem, and tighten the packing nut.
- Reassemble the handle, turn the water back on, and test for drips.
With the supply off, it is worth checking the rest of the bathroom while your tools are out. A dishwasher air gap leak across the counter shares the same shut-off valves and is easier to fix now than after you put everything away.
Tools and Supplies for the Job
- Adjustable wrench and stem wrench.
- Flathead and Phillips screwdrivers.
- Plumber’s tape and silicone grease.
- Replacement washers, O-rings, and valve seats.
- A bucket and rags for residual water.
| Symptom | Likely Cause | Part to Replace | Difficulty | Typical Cost |
|---|---|---|---|---|
| Drip from spout | Worn washer or cartridge | Washer or cartridge | Easy | $5-$15 |
| Drip around handle | Worn O-ring | O-ring | Easy | $3-$10 |
| Drip at the base | Loose packing nut | Packing or washer | Moderate | $5-$12 |
| Drip continues when closed | Corroded valve seat | Valve seat | Moderate | $8-$20 |
Repairing a Single-Handle Bathtub Faucet
Single-handle repairs center on the cartridge and take about 20 to 40 minutes.
- Shut off the water and plug the drain.
- Remove the handle screw and pull the handle straight off.
- Take off the retaining clip or nut that holds the cartridge in place.
- Pull the old cartridge with pliers or a cartridge puller.
- Install the new cartridge, replace the clip, and reassemble the handle.
- Turn the water back on and check both hot and cold positions for leaks.
If the drip continues with a fresh cartridge, test the supply pressure. A water heater pressure relief valve that weeps is a separate symptom of pressure running too high, and fixing it protects the whole plumbing system, not just the faucet.
Cartridge, Ball, and Ceramic Disc Valves
Single-handle faucets use cartridges, ball valves, or ceramic disc valves. Ceramic disc designs last the longest because two polished discs wear against each other with no rubber to rot, but the discs can chip if grit gets into the system. Ball valves have fewer parts and fail mainly at the springs and seals under the cap.
Common Mistakes to Avoid
- Skipping the shut-off and flooding the tub area.
- Forcing plastic parts instead of wiggling them free.
- Leaving old plumber’s tape on the threads.
- Over-tightening the cartridge and cracking the body.
Temporary Fixes, Costs, and When to Call a Pro
If the part is on order or you cannot get to the repair today, a few measures slow the damage.
Temporary Fixes That Slow the Drip
- Close the handle firmly and leave it closed.
- Tie a cloth around the spout to muffle the drip at night.
- Catch drips in a bucket and reuse the water on plants.
- Do not crank the handle harder, which damages the seat.
What the Repair Costs
The DIY route runs $10 to $25 in parts. A plumber’s visit typically starts at $150 to $350 for the service call and labor, plus parts, so the repair is one of the few plumbing jobs where the savings for doing it yourself are substantial. Bathroom leaks tend to travel together, and fixing a leaking toilet tank uses the same shut-off, drain, and replacement sequence as faucet work, so one session can clear several fixtures.
Signs You Need a Plumber
- Water stains or dampness on the ceiling or wall below the tub.
- Leaks from behind the wall or around the faucet base.
- Stripped threads or a cracked faucet body.
- No shut-off valves and no clear way to isolate the water.
Prevention, Maintenance, and Tracking Water Waste
Most faucet leaks are preventable, and the ones that happen are easier to catch early.
Maintenance Routines That Stop Leaks Early
- Turn handles gently and close them fully each time.
- Clean mineral deposits from the spout and aerator yearly.
- Replace washers and O-rings at the first sign of a drip.
- Exercise shut-off valves once a year so they stay usable.
The Math Behind the Drip
A bathtub faucet that drips steadily wastes close to 700 gallons a year, roughly 1.9 gallons a day, and the drip is usually the visible end of a slow failure. A drip on the hot side also wastes the energy used to heat that water, so the fix trims two bills at once. Catching it early means one $10 washer instead of a worn seat, a stained tub, or water working its way into the floor below.
Related Fixtures Worth Checking
The same visit should cover the toilet tank, supply lines, and shower valve, since they fail the same way and share the same shut-offs. The whole process comes down to diagnosing the problem and making the fix before the damage spreads, and most bathrooms can be made drip-free in a single afternoon.