That slow drip you hear at night is not just annoying, it is expensive. A leaky kitchen faucet dripping once per second wastes more than 3,000 gallons a year, enough to fill dozens of bathtubs, and the sound of it is enough to drive anyone up the wall. The good news is that most kitchen faucet leaks trace back to a handful of worn parts that cost a few dollars to replace.
You do not need to be a plumber to stop a common leak. With a screwdriver, an adjustable wrench, and maybe a $10 repair kit, most homeowners can fix the drip in under an hour. This guide covers where faucets leak, why they leak, and exactly how to diagnose and repair each type.
Where Kitchen Faucets Leak
Before fixing anything, pin down where the water is actually coming from. Leaks show up in three main places, and each points to a different worn part.
- The spout tip: a steady drip from the end of the spout when the faucet is off usually means worn seals, a bad cartridge, or corroded valve seats.
- The base of the spout: water pooling around the bottom where the spout meets the body points to failed O-rings.
- Under the sink: water collecting in the cabinet often comes from loose supply-line connections or a cracked cartridge, not the visible faucet at all.
Wipe everything dry, run the faucet, then watch closely to see which spot wets first. Getting the location right saves you from replacing the wrong part.
Identify Your Faucet Type
The repair depends entirely on the internal mechanism, and kitchen faucets come in four flavors. Compression faucets, the old two-handle design, use rubber washers that wear out and are the most common source of drips in older homes. Cartridge faucets use a removable cartridge that controls flow and temperature. Ball faucets, common in single-handle designs, use a rotating ball with springs and seats. Ceramic disc faucets use two polished discs and rarely fail.
To identify yours, note the handle setup. Two separate handles usually mean compression or cartridge. A single handle that moves up and down and side to side is a ball, cartridge, or disc type. If you can find the brand and model, a quick search reveals the exact internal parts and the matching repair kit.
Before You Start: Shut Off the Water
This step is non-negotiable. Reach under the sink and turn both shutoff valves clockwise until they stop, cutting hot and cold supply. If the under-sink valves are seized or missing, shut off the main water valve for the house. Open the faucet to relieve pressure and drain the lines.
Plug the drain with a rag or a sink stopper so you do not lose a tiny screw or spring down the pipe. Lay a towel in the sink and cabinet to catch drips and protect the basin. Line up your tools before disassembly: a flathead and Phillips screwdriver, an Allen wrench set, adjustable pliers, and plumber’s grease.
Fixing a Dripping Spout
A drip from the spout tip is the classic leak. For a compression faucet, the culprit is almost always a worn rubber seat washer. Pry off the decorative handle cap, remove the handle screw, lift the handle, and unscrew the packing nut to expose the stem. At the bottom of the stem sits a small washer held by a brass screw. Swap in an identical replacement, and while you are in there, inspect the valve seat for pitting.
For a cartridge faucet, the cartridge itself has usually failed. Remove the handle, pull the retaining clip with needle-nose pliers, and lift the old cartridge straight out. Take it to the store to match a replacement exactly, since brands differ. Coat the new cartridge O-rings with plumber’s grease and press it in, aligning any tabs. Ball and disc faucets get a rebuild kit with new springs, seats, or a disc set.
Fixing a Leak at the Base
When water seeps out around the bottom of the spout as you run the faucet, the O-rings that seal the rotating spout have hardened or cracked. This is one of the easiest fixes. Shut off the water, remove the handle and spout by lifting it off the faucet body, and slide the old O-rings off with your fingers or a pick.
Bring the old rings to the hardware store to match the diameter precisely, since an O-ring that is even slightly off will keep leaking. Coat the new ones in plumber’s grease, roll them onto the spout base, and reseat the spout with a gentle twist. Turn the water back on and run it while watching the base stay dry.
Leaks Under the Sink
Water in the cabinet is a different problem. Check the compression nuts where the flexible supply lines connect to the shutoff valves and to the faucet tailpieces. A quarter turn with a wrench often stops a slow weep, but do not overtighten, since that can crack a fitting. If a braided supply line is corroded or bulging, replace it outright; they cost about $8 and are cheap insurance against a burst.
If the water appears only when the faucet runs and traces up to the faucet body, the cartridge or a cracked faucet base may be leaking internally down into the cabinet. That usually calls for a cartridge replacement or, if the body is cracked, a new faucet.
Cleaning Mineral Buildup and Clearing the Aerator
Not every faucet problem is a leak; sometimes what looks like a malfunction is just hard-water scale. If the flow has weakened or sprays sideways, unscrew the aerator at the tip of the spout and soak it in white vinegar for an hour to dissolve the calcium deposits, then scrub it with an old toothbrush and reinstall. This five-minute fix restores flow and often stops the erratic spray that gets mistaken for a leak.
Mineral buildup also attacks the internal parts that cause drips. When you have a cartridge or ball faucet apart, soak the metal and ceramic pieces in vinegar to clear scale from the sealing surfaces, since even a new washer will weep if it seats against a crusted valve. In hard-water areas, this scale is the reason faucets need rebuilding more often, and a whole-house softener dramatically extends the life of every valve and seal in the house.
Tools and Parts to Keep on Hand
Being ready turns a stressful drip into a quick fix. Stocking a small kitchen-repair kit means you are not running to the store with the water shut off and the sink half apart. A well-prepared homeowner keeps these items in the cabinet under the sink or in a nearby toolbox.
- An assortment of rubber seat washers and O-rings sized to your faucet
- Plumber’s grease for lubricating cartridges and O-rings
- A universal cartridge or the specific replacement for your faucet brand
- An adjustable wrench, a basin wrench, and channel-lock pliers
- A roll of Teflon plumber’s tape for supply connections
- A spare braided stainless supply line or two
Knowing your faucet’s brand and model before trouble strikes is half the battle, since matching parts is the step that trips people up. Snap a photo of the faucet’s label or the underside markings and keep it with the parts kit so a future repair goes smoothly.
When to Replace Instead of Repair
Sometimes a repair is throwing good money after bad. Consider a full replacement if the faucet is more than 15 years old, the finish is flaking and corroded, replacement cartridges are discontinued, or you have already rebuilt it once and it leaks again. A decent mid-range kitchen faucet runs $80 to $250, and installation is a manageable DIY job with a basin wrench.
Do not ignore a persistent drip. Beyond the wasted water, a chronic leaky kitchen faucet can stain the sink, corrode fixtures, and hide a slow cabinet leak that rots the base and breeds mold. Diagnose the source, match the right parts, and most leaks surrender to an hour of careful work. If a leak returns after two honest repair attempts, that is your signal to swap the faucet or call a plumber.
