Bathroom Faucet Is Leaking: How to Find and Fix the Drip Yourself

Updated November 2026

A bathroom faucet is leaking for one of a few predictable reasons: a worn washer or O-ring, a failed cartridge, a loose handle, or a damaged valve seat. This guide shows you how to identify which part is failing, shut off the water safely, and make the repair with basic hand tools. Most single-handle and two-handle faucets can be fixed in under an hour.

Find Out Where the Leak Is Coming From

Before you take anything apart, figure out whether the water is dripping from the spout or leaking around the base of the handle. A drip from the spout usually points to a worn cartridge, washer, or valve seat. Water seeping out around the handle or base usually points to a worn O-ring or a loose packing nut.

Shopping for one? See our guide: Bathroom Leaking Faucet Repair: 6 Best Repair Kits Compared (2026).

Dry the faucet, then watch it for a minute with a paper towel under the spout. If the drip is constant even with the handle off, the seal inside is the likely culprit. If it only drips when the handle is in the “off” position, the cartridge or washer is not closing fully.

Shut Off the Water and Prepare the Work Area

1. Locate the shutoff valves under the sink and turn them clockwise until snug.
2. Open the faucet to drain remaining water and confirm nothing flows.
3. Plug the sink drain so small parts cannot fall in.
4. Lay a towel in the basin to protect the finish and cushion dropped parts.
5. Gather a flathead and Phillips screwdriver, an adjustable wrench, a small Allen wrench set, plumber’s grease, and replacement parts.

Replace the Worn Part

Replacing a Washer or O-Ring

On older compression faucets, remove the handle screw, unscrew the packing nut, and lift out the stem. Pull the rubber washer off the bottom of the stem and replace it with an identical one. Check the O-ring on the stem and coat it with plumber’s grease before reassembly.

Replacing a Cartridge

Most modern single-handle faucets use a cartridge. Remove the handle set screw, lift off the handle and trim cap, unscrew the retaining nut or clip, and pull the cartridge straight out. Match the new cartridge to the old one by brand and model. Seat it with the tab aligned to the body, then reassemble and test.

Reassemble, Test, and Check for Leaks

Reassemble in reverse order and tighten fasteners snugly without overtorquing, since overtightening cracks plastic and stresses seals. Slowly reopen the shutoff valves, turn the faucet on, and run hot and cold water for a few minutes. Then turn the handle off and wait 10 minutes. If the spout stays dry, the repair is complete. If you still see a drip, recheck the seating of the new part.

Common Mistakes to Avoid

• Skipping the shutoff valves, which leads to a flood in the cabinet.
• Buying a replacement cartridge by “looks like” instead of brand and model number.
• Forgetting plumber’s grease on O-rings, which causes them to tear on reinstall.
• Overtightening the retaining nut and cracking the body.
• Ignoring hard water buildup on the valve seat, which can cause a leak even with a new cartridge.

Recommended Gear

• Plumber’s grease helps O-rings seal and slide smoothly. View on Amazon
• Basin wrench reaches the nuts under a sink when space is tight. View on Amazon
• Faucet repair kit bundles common washers, O-rings, and seats so you have spares on hand. View on Amazon

If you want to see how specific brands handle this repair, related guides such as Moen Bathroom Faucet Cartridge: 4 Best Replacements Compared (2026) and Repair Dripping Faucet Bathroom: A Step-by-Step Guide for Beginners walk through brand-specific steps. For parts identification, see Moen Bathroom Faucet Parts: Identify, Order and Replace Them Yourself.

FAQ

Can I fix a bathroom faucet leak without replacing the whole faucet?

Yes. In most cases the leak comes from a washer, O-ring, or cartridge, which are inexpensive, replaceable parts. Replacing the whole faucet is rarely necessary unless the body itself is cracked or corroded.

How do I know which replacement part I need?

Check the faucet brand and model, usually printed on the handle or under the cap. Remove the old part and bring it to a hardware store or match it against the manufacturer’s parts diagram before buying.

Should I call a plumber for a leaking faucet?

If the faucet is simple and you can shut off the water, most homeowners can handle the repair. If the valve body is damaged, pipes are corroded, or you are unsure about shutoff valves, consult a licensed plumber.

Conclusion

A bathroom faucet that is leaking usually needs one worn part replaced, not a new faucet. Identify where the water is coming from, shut off the supply, and swap the washer, O-ring, or cartridge with an exact match. Test thoroughly, and your faucet should run dry again.

Related reading

• Bathroom Tub Faucet Leaking: Find the Source and Fix It Yourself

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