Fix a Leaky Faucet

A leaky faucet is one of those repairs that feels bigger than it is. That drip you hear at night, the slow pooling under the sink, the waste of water and money—it nags at you. The good news is that fixing it doesn't require calling a plumber. Nearly every faucet leak traces back to the same handful of worn internal parts, and swapping them out is straightforward work. You'll need basic tools, maybe an afternoon, and the confidence that comes from knowing exactly what's wrong and how to fix it. A faucet that drips once per second wastes about 3,000 gallons a year. That's worth fixing yourself.

1. Shut Off Water First. Locate the shutoff valves beneath the sink—there should be one for hot water and one for cold. Turn both clockwise until they stop. Open the faucet and let any remaining water drain out. If you don't have shutoff valves under the sink, turn off the main water supply to the house at the meter or main shutoff valve, then open a lower faucet in the house to depressurize the lines.
2. Document Before Detaching. Look for a small set screw or cap on the handle itself—this is often hidden under a decorative cover or plug. Pry off any cover with a flathead screwdriver, then unscrew the set screw with an Allen wrench or screwdriver. Pull the handle straight up and off. Some handles are held by a single screw visible from the side; unscrew that instead.
3. Unscrew the Packing Nut. Under the handle, you'll see a large hexagonal nut (the packing nut). Use an adjustable wrench to loosen and unscrew it by turning counterclockwise. Turn it by hand once it's loose enough. Set it aside in a safe place—don't drop it down the sink.
4. Extract the Worn Part. Depending on your faucet type, you'll now see either a stem (single-handle faucets often have this) or a cartridge (two-handle faucets typically use this). For a stem, turn it counterclockwise with a stem wrench or adjustable wrench until it comes free—it may take several full turns. For a cartridge, pull straight up to remove it. If it won't budge, use a cartridge puller tool (a small investment worth making). Place the old part on the counter to compare when buying the replacement.
5. Swap Seals and Washers. If you removed a stem, look at the rubber washer at the bottom—this is almost always the culprit in a dripping faucet. Pry it out with a flathead screwdriver and replace it with an identical new one. Also check the small O-ring around the stem; if it looks cracked or degraded, replace it too. If you removed a cartridge, the internal seals are often not user-replaceable, so replacement of the entire cartridge is the fix. Set aside any rubber parts you're replacing.
6. Clear Mineral Buildup. Inside the faucet body where the stem or cartridge sat, you'll see a small conical or flat surface called the valve seat. Mineral deposits, rust, or debris here can prevent a tight seal even with new washers. Wipe it clean with a damp cloth or use a valve seat dresser tool if it's heavily pitted. For most home faucets, a cloth and a little white vinegar will do the job.
7. Reinstall the Part. Place the new or cleaned stem back into the faucet body. If it's a stem, align the flat side with the corresponding flat in the body and turn it clockwise until hand-tight. Don't force it—it should turn smoothly. If it's a cartridge, push it straight in until it seats fully. You may feel or hear a click indicating proper seating.
8. Hand-Snug, Quarter-Turn. Screw the packing nut back onto the faucet body by hand first, then tighten it with an adjustable wrench. Turn it clockwise until snug—don't over-tighten or you'll crack the nut or make the handle hard to turn. Hand-tight plus a quarter-turn with the wrench is usually right.
9. Reattach the Handle. Align the handle with the faucet body in the off position (handle pointed down for most faucets). Slide it back onto the stem or cartridge, then tighten the set screw with an Allen wrench or screwdriver. Snap the decorative cap back over the screw if there is one. The handle should be snug but not over-torqued.
10. Verify the Fix. Open the shutoff valves under the sink by turning them counterclockwise. Open the faucet and let water run for a minute to flush any debris. Close the faucet and watch the spout and the base of the faucet for any leaks. Let it sit for five minutes, then check again. If water is still dripping from the spout, you may need to tighten the packing nut slightly or repeat the washer replacement.
11. Watch for Hidden Leaks. Place a bucket or towel under the shutoff valves and the base of the faucet. Wait 30 minutes and check if any water has pooled. If the packing nut area is wet, tighten it a quarter-turn and wait again. If the shutoff valves are leaking, you'll need to replace the valve washers or the valves themselves—another simple repair but a separate one.