A dripping kitchen faucet is usually a worn-out cartridge. Replacing it is a reasonable weekend project for a handy homeowner.
I’m Aron Oretan, a Licensed Red Seal Plumber and Steamfitter with 26 years in the trade. Here is how I fix a dripping kitchen faucet, and when I’d tell you to call a pro instead.
Why a Dripping Kitchen Faucet Keeps Dripping
Most modern single-handle faucets, including Delta and Moen, use one internal cartridge. It controls both flow and temperature. Over time, that cartridge wears out and the faucet starts to drip.
Hard water speeds this up. In 2025, the City of London’s drinking water report measured hardness between 110 and 126 mg/L. That is roughly 6.5 to 7.5 grains per gallon. Minerals build up on the cartridge and wear it down. A water softener cuts that buildup.
Replacing a cartridge costs far less than buying a new faucet. That is usually where I start.
Where Is Your Dripping Kitchen Faucet Leaking?
Check where the water shows up before you buy parts. Water dripping from the spout points to the cartridge. Water pooling around the base of the spout usually means worn O-rings.
This guide covers the cartridge, since that is the most common cause.
5 Steps to Fix a Dripping Kitchen Faucet
1. Shut off the water. Close both supply valves under the sink. Open the faucet to release the pressure. Put a towel in the basin. A set screw lost down the drain is a mistake you only make once.
2. Remove the handle. Many single-handle faucets hide a set screw under the hot/cold indicator cap. Pop the cap off, loosen the screw with an Allen key, and lift the handle away. Work slowly so you don’t scratch the finish.
3. Pull the old cartridge. Remove the cap or nut over the cartridge, then take out any retaining clip. Pull the cartridge straight up. It will be scaled up if your water is hard. Check the housing for debris.
4. Install a matching cartridge. Cartridges are brand and model specific. Take the old one with you to match it. Line up the alignment tabs before you seat the new one. A misaligned cartridge is a common reason DIY repairs leak later.
5. Reassemble and test. Tighten the nut or clip and reinstall the handle. Open the supply valves slowly. Check that the dripping kitchen faucet has stopped and the pressure is normal.
When to Call a Plumber for a Dripping Kitchen Faucet
Call a plumber if the shut-off valves won’t close, the nut is seized, or the supply lines are corroded. Forcing a seized part can turn a small repair into a flood. At that point, a licensed plumber costs less than the water damage.
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Frequently Asked Questions
Why is my kitchen faucet still dripping after I tightened it?
A worn or scaled cartridge is the usual cause, not a loose handle. Tightening won’t fix it.
How do I stop a dripping kitchen faucet?
Shut off the water, remove the handle, and replace the worn cartridge with a matching one. The five steps above walk through it.
How do I know if it’s the cartridge or the O-rings?
Dripping from the spout points to the cartridge. Water around the base of the spout usually means worn O-rings.
Can I use any cartridge in my faucet?
No. Cartridges are brand and model specific. Bring the old one to match it, or have a plumber identify it for you.
Is hard water the cause of a dripping kitchen faucet?
It speeds it up. Mineral buildup wears the cartridge and seals. London’s treated water measured roughly 6.5 to 7.5 grains per gallon in 2025.
Should I repair or replace a dripping kitchen faucet?
If a matching cartridge is available, repairing costs far less than a new faucet. If the faucet is badly corroded or parts are discontinued, replace it.
When should I call a plumber?
Call one if the shut-off valves won’t close, the nut is seized, or the supply lines are corroded.
Author bio: Aron Oretan is the owner of Triton Home Service, a Licensed Red Seal Plumber and Steamfitter with 26 years in the trade, serving London, St. Thomas, and Oxford County.
