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Most leaky kitchen faucets can be fixed in under an hour with basic hand tools and a replacement part. The key is figuring out where the water is escaping, because a drip from the spout, a seep around the handle and a puddle under the sink each point to a different worn component. This guide shows you how to fix a leaky kitchen faucet by locating the leak, shutting off the water safely, replacing the failed part and testing your repair.
Find Where the Leak Is Coming From
Before you take anything apart, spend a few minutes figuring out exactly where the water is coming from. The fix depends on the source, and replacing the wrong part wastes time and money. Run the faucet, dry the area, then watch closely.
Leaks From the Spout
If water drips from the spout when the handle is off, the problem is almost always inside the valve. In single-handle faucets, the cartridge controls water flow and temperature, and a worn cartridge lets water slip past its seals even when closed. In two-handle faucets, the culprit is usually a worn washer or valve seat. Owners often report that a faint, steady drip starts gradually and gets worse over months, which is typical of seal wear rather than a sudden failure.
Leaks Around the Base of the Handle
Water that seeps out around the handle or collects at its base usually means the O-rings or cartridge seals have worn out. Water pressure forces moisture past these seals and up through the handle assembly. This is a good sign that the problem is contained within the faucet body and not in the plumbing.
Leaks Under the Sink
If you find water pooling in the cabinet, check the supply lines (the flexible hoses running from the shutoff valves to the faucet), the compression nuts where those hoses connect, and the mounting nut underneath the faucet. A drip from the P-trap is a drain problem and is handled differently, so confirm the water is coming from the faucet connections before you start.
| Symptom | Most likely cause | Typical fix |
|---|---|---|
| Drip from spout when handle is off | Worn cartridge, washer or valve seat | Replace cartridge or valve parts |
| Water around handle base | Worn O-rings or cartridge seals | Replace O-rings, or the cartridge |
| Drip from spray head or hose | Damaged hose or diverter valve | Replace the spray head, hose or diverter |
| Puddle under sink, faucet dry | Loose supply line or compression nut | Tighten or replace the supply line |
| Leak at base of faucet body | Failed gasket or loose mounting nut | Tighten nut or replace the base gasket |
Tools and Parts You Will Need
Gather everything before you shut off the water. Stopping halfway to hunt for a part can leave you with a sink that has no water and no way to restore it quickly.
- Replacement cartridge, valve kit or O-ring kit that matches your faucet’s brand and model number
- Hex (Allen) key set, usually including the size that fits the handle set screw
- Flathead and Phillips screwdrivers
- Adjustable wrench or basin wrench
- Towels and a shallow bowl or tray for small parts
- Plumber’s silicone grease for lubricating O-rings
- Old toothbrush and white vinegar for cleaning mineral deposits
- Flashlight for working under the sink
Match the replacement part by checking the faucet’s model number, usually printed on the underside of the spout, on the base or in the original packaging. Manufacturers specify exact cartridge and seal numbers for each model, and a part that looks similar can still fail to seal properly.
How to Fix a Leaky Kitchen Faucet, Step by Step
The following process covers most single-handle faucets with a cartridge, which is the most common type of leak repair. Two-handle and ball-type faucets follow the same general logic, but the internal parts differ, so check your manufacturer’s diagram if your faucet is laid out differently.
Step 1: Shut Off the Water
Look under the sink for two shutoff valves, one on the hot line and one on the cold line. Turn each one clockwise until it stops. If the faucet has a separate shutoff for a spray or filter line, close that too. Then open the faucet to drain remaining water from the lines. If the valves do not stop the flow or they drip when closed, shut off the main water supply at the meter and call a plumber to look at the valves before you rely on them.
Step 2: Remove the Handle and Decorative Cap
Most handles have a decorative cap or button on top. Pry it off gently with a flathead screwdriver or a fingernail. Under it, you will find a set screw. Loosen it with the correct hex key, then lift the handle straight up. If the handle is stuck, do not force it; a slight wiggle while lifting usually frees it from the stem.
Step 3: Remove the Retaining Clip and Cartridge
Once the handle is off, you will see a retaining clip or nut holding the cartridge in place. Remove it and note how it sits. Some manufacturers use a metal clip that needs to be lifted with a small screwdriver. Pull the cartridge straight up. Use a cartridge puller if it resists, and avoid twisting, which can damage the valve body.
Step 4: Inspect the Cartridge and Valve Body
Look at the cartridge for cracks, grit and hard mineral crust. Check the valve body inside the faucet for scale. Clean any deposits with white vinegar and a soft toothbrush. Do not scrape metal surfaces with anything abrasive, since you could scratch the finish or seating surfaces.
Step 5: Replace the Cartridge or O-Rings
If the cartridge is worn, replace it with an exact match. If the cartridge looks fine but the handle still weeps, replace the O-rings on the cartridge and the body. Lightly coat new O-rings with plumber’s silicone grease before installing. Avoid petroleum-based grease, which can degrade rubber seals over time.
Step 6: Reassemble the Faucet
Reverse the disassembly. Seat the cartridge with its alignment tab or notch lined up with the valve body, then reinstall the retaining clip. Slide the handle back on, tighten the set screw snugly without overtightening, and snap the decorative cap in place.
Step 7: Turn the Water On and Test
Open the shutoff valves slowly, a quarter turn at a time, and check for leaks at every connection. Run the faucet on hot and cold, then turn it off and watch the spout for at least a minute. A proper repair should stop the drip completely. If you still see water, shut off the supply and recheck the cartridge seating and O-rings.
Fixing Leaks Under the Sink
If the faucet body is dry but water collects under the cabinet, the problem is in the supply connections rather than the valve. Dry the area completely, then inspect each connection with a flashlight and a paper towel. Hand-tighten each compression nut first, then give it a quarter turn with a wrench. Overtightening can crack the nut or the fitting.
Supply lines that are old, cracked or stiff should be replaced rather than patched. Braided stainless steel supply lines are widely sold for this purpose and are typically matched to standard shutoff valve sizes, so check the threads and length before buying. If the shutoff valve itself leaks around the stem, it may need replacement, which is a job best handled by a licensed plumber, especially if the valve is corroded or the water cannot be fully shut off.
Common Mistakes and Tips
- Skipping the shutoff check. Confirm the water is off by opening the faucet before removing anything. Water left in the lines can spray when a part comes loose.
- Buying by look alone. Two cartridges can look alike and still be incompatible. Always match the brand and model number.
- Overtightening. Hand-tight plus a small turn is usually enough for compression nuts and handle set screws. Excess torque cracks plastic and strips threads.
- Using the wrong lubricant. Plumber’s silicone grease is designed for rubber seals. Petroleum jelly and some household oils can swell or break down O-rings.
- Ignoring the aerator. A clogged aerator changes spray pattern but does not cause drips. Clean it separately, and do not assume it is the leak source.
- Taking photos before you disassemble. A quick photo of the cartridge orientation and clip placement makes reassembly far easier.
- Waiting too long to replace. A faint drip often means worn seals that will eventually damage the valve body. Replacing a cartridge early costs less than replacing the whole faucet.
For ongoing prevention, flush the valve periodically and wipe down the spout and handle to limit mineral buildup. Our guide to Kitchen Faucet Maintenance: Cleaning, Leaks and Aerators“>kitchen faucet maintenance covers routine care that reduces the chance of leaks. If your faucet is a single-control model, the Single-Handle Kitchen Faucets: Control, Cartridges, Care“>cartridge and care details explain how these parts are arranged and what to expect when replacing them.
Recommended Gear
These items make the repair easier and reduce the chance of damaging parts. Confirm compatibility with your faucet before buying.
- Plumber’s silicone grease: Lubricates O-rings without breaking down rubber seals. A small tube lasts through many repairs. Check price on Amazon
- Cartridge puller: Helps remove a stuck cartridge without twisting the valve body. Check price on Amazon
- Basin wrench: Reaches mounting nuts and supply connections in tight spaces under the sink. Check price on Amazon
- Replacement cartridge kit: Matched to your faucet’s brand and model, so the seals and fit are correct. Check price on Amazon
FAQ
Why does my faucet keep dripping after I replaced the cartridge?
The most common cause is incorrect seating. Check that the cartridge’s alignment tab is fully engaged in the valve body and that the retaining clip is seated correctly. Debris on the seating surface or a damaged O-ring can also cause a leak, so inspect those before reinstalling.
Can I fix a leaky faucet without shutting off the main water?
Often yes, if the shutoff valves under the sink work properly and seal fully. If they do not, you will need to shut off the main supply at the meter or the house shutoff. If you are unsure about the valves, a licensed plumber can check them.
How long does it take to fix a leaky kitchen faucet?
A cartridge or O-ring repair usually takes 30 to 60 minutes for someone working through the steps for the first time. Supply line replacement adds time, and stubborn corrosion can make the job longer.
When should I replace the whole faucet instead of repairing it?
Consider replacement if the body is corroded or cracked, parts are no longer available for your model, or the faucet keeps leaking after a proper cartridge replacement. Repeated repairs on an aging faucet can cost more than a new unit over time.
Is it safe to do this repair myself?
For most cartridge and O-ring repairs, yes, as long as you shut off the water first and handle the parts carefully. If the shutoff valves leak, the plumbing is corroded or you smell gas or see signs of damage to the plumbing, stop and consult a licensed plumber.
