How to Fix a Leaking Bathtub Faucet

A bathtub faucet that drips when turned off wastes water constantly and can leave rust stains in your tub. The fix is almost always a worn internal part — and you can replace it yourself in under an hour.

Why Bathtub Faucets Leak

Bathtub faucets are typically two-handle designs (separate hot and cold) or single-handle. The most common causes of leaking:

Worn seat washer — the rubber washer at the bottom of the stem wears flat and can no longer seal
Worn O-rings — rubber rings on the stem that seal against the valve body
Worn seats and springs — the small components that create the watertight seal
Worn cartridge — in single-handle tub faucets

What You Need

Faucet stem repair kit — includes cartridge, seats, springs for two-handle faucets
PTFE thread seal tape
Rubber strap wrench
Screwdrivers, adjustable wrench, plumber's grease

Step-by-Step Fix

Step 1: Turn off the water supply.
Bathtub faucets don't have individual shut-off valves — turn off the main water supply or the bathroom shut-off if available. Turn on the tub faucet to drain remaining water.

Step 2: Identify which handle is leaking.
For two-handle faucets, turn off one supply at a time to determine if it's the hot or cold side. This tells you which stem to replace.

Step 3: Remove the handle.
Pry off the decorative cap, unscrew the handle screw, and pull the handle off. Some older handles are stuck — use a handle puller or gently wiggle while pulling.

Step 4: Remove the stem.
Use a deep socket wrench or adjustable wrench to unscrew the packing nut. Pull out the stem assembly.

Step 5: Replace worn parts.
Inspect the seat washer at the bottom of the stem — replace it if flattened or cracked. Replace the seat springs using your faucet stem repair kit. Replace any cracked O-rings on the stem body.

Step 6: Reassemble.
Apply plumber's grease to all rubber parts and O-rings. Wrap threaded connections with PTFE tape. Reinstall the stem, packing nut, and handle.

Step 7: Test.
Turn the water supply back on slowly. Check for dripping at the spout and leaking around the handle.

Special Case: Leaking Tub Spout

If water drips from the tub spout even when the shower is running (diverter issue), the diverter valve inside the spout is worn. You can replace just the spout — most unscrew counterclockwise or have a set screw underneath.

When to Call a Plumber

The valve body inside the wall is corroded or cracked
You can't find replacement parts for an old or unusual faucet
Water is leaking inside the wall behind the tub

Bottom Line

A leaking bathtub faucet is almost always a worn washer, O-ring, or cartridge. Turn off the main water, remove the handle, replace the worn parts, and reassemble. Most repairs take under an hour and cost less than $20.

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