Symptoms
- Single lever handle
- Drip continues no matter the handle position
- Drip is worse right after use
- Handle feels loose or gritty when moving
Likely causes
- CommonWorn or scored cartridgeThe cartridge's seals degrade over years of use and stop blocking flow fully.
- CommonMineral deposits inside the cartridgeHard water buildup keeps the internal seals from seating properly.
- PossibleDamaged O-rings on the cartridgeCan cause drips or leaks around the base as well as the spout.
- Less commonWrong or off-brand replacement cartridgeA near-fit cartridge can leak even when new.
What to do
- Shut off the hot and cold supply valves under the sink and open the faucet to relieve pressure.
- Remove the decorative cap, handle screw, and handle to expose the cartridge retaining clip or nut.
- Take a photo of the orientation before removing the cartridge so the replacement goes in the same way.
- Pull the old cartridge straight out, using pliers to grip the stem if it's stuck.
- Bring the old cartridge to a hardware store or check the faucet brand and model to buy an exact match.
- Insert the new cartridge in the same orientation, replace the retaining clip or nut, and reattach the handle.
- Turn the water back on slowly and run hot and cold for a minute to clear any debris.
- Check under the sink and around the base for leaks after the first few uses.
Tools and parts
- Adjustable wrench
- Screwdriver
- Pliers
Faucet cartridge (brand-matched)Search: “replacement faucet cartridge [faucet brand/model]”
When to call a pro
Call a plumber if you can't identify the faucet brand/model, the cartridge won't budge, or the leak persists with a new cartridge.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.