Quick answer: A dripping faucet is almost always a worn cartridge, O-ring, or (on older faucets) a washer/seat. It’s a $5–$15 fix you can do in 15–30 minutes with basic tools. A single dripping faucet can waste thousands of gallons a year, so it’s worth fixing fast. Here’s how a licensed plumber does it.
Complete guide to fixing a leaky faucet, written by a licensed plumber, with the exact parts for each fix.
Step 1: Shut Off the Water and Plug the Drain
Turn off the two shut-off valves under the sink and open the faucet to release pressure. Put a rag in the drain so small parts can’t fall in.
Step 2: Identify Your Faucet Type
Cartridge, ball, ceramic-disc, or compression — the type decides the fix. Most modern faucets are cartridge-style, which is the easiest to repair.
Step 3: Replace the Cartridge (most common fix)
Pop off the handle cap, unscrew the handle, pull the old cartridge, and drop in a matching new one. Take the old part to the store to match it exactly. See the best faucet cartridge replacements.
Step 4: Check O-Rings and the Aerator
If the leak is at the base or spout, worn O-rings are usually the cause — replace them and add plumber’s grease. If the faucet sputters or has weak flow, the fix is often just a clogged aerator you can unscrew and clean or replace.
Step 5: Sprayer and Supply Line
A weak or leaking sprayer is a cheap swap — see kitchen faucet sprayer replacements. And while you’re under the sink, a fresh braided supply line is cheap insurance against a future leak.
When to Call a Plumber
Call a pro if the valve body itself is cracked, the shut-offs won’t close, or water is leaking inside the cabinet/wall rather than from the faucet.
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FAQ
Why is my faucet dripping even after I turned it off tight?
Forcing the handle won’t help — the internal cartridge, washer, or O-ring is worn. Replace it rather than over-tightening, which causes more damage.
How much does it cost to fix a dripping faucet?
DIY, usually $5–$15 in parts. A plumber typically charges $75–$200, so this is one of the best money-savers to do yourself.
Can a dripping faucet raise my water bill?
Yes — a steady drip can waste thousands of gallons a year, which adds up on a metered bill.