Kitchen Faucet Dripping or Leaking? Causes and Repairs

A dripping kitchen faucet is easy to tune out, but the waste adds up. The EPA’s WaterSense program estimates that a faucet dripping once per second can waste more than 3,000 gallons a year. A leak at the base of the faucet or under the sink is worse, because water that never reaches the drain can soak the cabinet, swell the sink base, and go unnoticed for months.

The right fix depends on where the water is coming from. A drip from the spout, a puddle around the base, a wet handle, and a damp cabinet floor are four different problems with four different causes. This guide helps you identify which one you have, explains what is realistic to fix yourself, and points out when a leak is a symptom of something bigger.

Start by Locating the Leak

Before buying parts, spend ten minutes finding the actual source.

1. Dry everything. Wipe the faucet, the countertop around it, and the supply lines and connections under the sink.
2. Lay dry paper towels in the cabinet beneath the faucet so new moisture shows up clearly.
3. Test in stages. Check with the faucet off, then run it on hot, then cold, then use the sprayer or pull-down head if you have one. Watch each location after each step.
4. Check the drain separately. Fill the sink and release it. Leaks that only appear while draining usually come from the drain trap or basket strainer, not the faucet.

A leak that appears only when the water is running points to the faucet body, handle, or hose. A leak that appears even when the faucet is off, or only when the supply valves are open, points to a supply line, valve, or connection under the sink.

Why a Kitchen Faucet Drips From the Spout?

A steady drip from the spout means the faucet’s internal shutoff isn’t sealing. What’s inside depends on the faucet type.

Worn Cartridge or Seals (Single-Handle Faucets)

Most modern single-handle faucets use a replaceable cartridge. When its internal seals wear, water slips past even with the handle closed. The cartridge is the most common culprit in a dripping single-handle faucet, and replacing it is a standard repair.

Worn Washers and Seats (Compression Faucets)

Older two-handle faucets use rubber washers pressed against a metal seat. The washer wears down, or the seat becomes pitted, and the faucet drips from the spout. A dripping faucet that stops when you tighten one handle harder usually has a worn washer on that side.

Ball and Ceramic Disc Faucets

Ball-type faucets, common in older single-handle designs, depend on small rubber seats and springs that wear out. Ceramic disc faucets are durable, but their seals and the disc cylinder can fail, especially if debris or scale gets between the discs.

Mineral Scale Interfering With the Seal

In Las Vegas, where the water supply carries a significant mineral load (see the Southern Nevada Water Authority’s published water-quality data), scale can build up on cartridges, seats, and discs and keep them from sealing cleanly. That is one possible cause, not the default one. Most faucet drips come from ordinary wear, and a faucet that is 10 or 15 years old would likely need new internal parts anywhere in the country. If you do find a crusty white deposit on the parts you remove, our article on how hard water affects faucets and plumbing fixtures explains how mineral scale differs from corrosion and what each does to metal components.

Why Water Leaks From the Base or Handle?

Leaking Around the Base of the Spout

Swivel spouts rely on rubber O-rings where the spout meets the faucet body. When they harden or wear, water works its way out around the base whenever the faucet is on. The fix is usually replacing the O-rings, though it requires disassembling the spout.

Leaking at the Handle

Water escaping from the handle usually points to a worn cartridge, a loose retaining nut, or a worn O-ring or packing seal. Because the handle is directly above the cartridge, a leak here and a drip from the spout often have the same root cause.

Water Pooling Where the Faucet Meets the Sink

If water collects under or around the faucet body itself, the cause may be a loose mounting nut below the sink, a deteriorated gasket between the faucet and the countertop, or a failed internal seal. This is worth correcting promptly, because water can seep into the countertop edge and the cabinet below.

Leaks Under the Sink That Aren’t Really “Faucet” Leaks

Many homeowners who think the faucet is leaking are looking at a nearby connection.

• Supply lines. The flexible lines from the shutoff valves to the faucet can leak at the fittings, or fail at the braid. Manufacturers generally recommend replacing flexible supply lines periodically, and the interval varies by product, so check the documentation.
• Shutoff valves. Older valves can weep from the stem when they have not been turned in years. The valves in many homes have never been operated.
• Pull-down or pull-out sprayer hose. The hose connections beneath the sink can loosen, and the hose or its weight can wear through over time.
• Drain components. The trap, slip nuts, and basket strainer are separate from the faucet but frequently get blamed for it.
• Water filter or dispenser lines. If you have an under-sink filter or instant-hot unit, its fittings are another potential source. (A point-of-use filter and a whole-house softener do different jobs, so check which system’s plumbing you are looking at.)

A slow leak in this area is one of the more common ways to end up with a hidden problem. The cabinet floor is often particleboard that swells and crumbles when wet, and mold can follow if the leak persists. See our guide to the signs of a hidden water leak for the warning signs, including a musty cabinet odor, swollen cabinet panels, and unexplained increases in your water bill.

Problems That Look Like Leaks

Some faucet symptoms are annoying but don’t involve a leak at all.

• Spray that splits or sputters. A clogged aerator (the screen at the tip of the spout) is the usual cause. Unscrewing it and soaking it in vinegar to dissolve mineral deposits is a reasonable first step.
• Water spraying sideways from the aerator. Same cause. Debris or scale partially blocks the flow.
• Low flow from only one faucet. This is often a clogged aerator or cartridge. If every fixture in the house is affected, see our guide on why water pressure suddenly drops.
• A handle that is stiff or doesn’t fully shut off. This often indicates a worn or scaled cartridge, not a leak yet, but it’s an early warning.

What You Can Reasonably Fix Yourself?

Faucet repairs are a common DIY project because the work involves no gas, no electrical components, and no hot-water tank. With the water off at the fixture, the risk is low.

Reasonable DIY repairs:

• Cleaning the aerator
• Replacing a cartridge, O-rings, or washers
• Tightening a loose handle or mounting nut
• Replacing a flexible supply line when the shutoff valve works properly

Before you start:

• Close both shutoff valves under the sink (clockwise) and open the faucet to confirm the water has stopped. If the valves don’t shut off completely, stop. That is a separate problem.
• Identify the faucet brand and model before buying parts. Cartridges and O-rings are not interchangeable across brands, and often not across models from the same brand.
• Take photos as you disassemble, and keep the small parts in order.
• Plug the sink drain so a dropped screw doesn’t disappear.

When to Call a Professional

A faucet repair that looks simple can turn out not to be. Consider calling a plumber or experienced handyman when:

• The shutoff valves won’t close fully or leak when turned. Old valves often fail when first operated in years. Forcing them can cause a worse leak.
• The leak is under the sink and you can’t trace it. Misdiagnosis wastes time while damage continues.
• The cabinet floor is soft, swollen, or discolored. There may be more damage than the leak itself, and our articles on water damage to drywall and mold after water damage explain what to look for.
• The faucet body, not an internal part, is corroded or cracked. That means replacement, not repair.
• The mounting hardware is stuck or the faucet is installed in a stone countertop. Quartz, granite, and similar materials make it easy to cause expensive damage with the wrong tool.
• You’ve replaced the cartridge or seals and it still leaks. A damaged seat or body may be the underlying issue.
• Several fixtures have recurring leaks. That might point to a broader supply problem.

For these situations, our kitchen faucet repair and installation services in Las Vegas can diagnose the source, repair what’s repairable, and replace what isn’t.

Repair or Replace the Faucet?

Repair is usually the right first move when the faucet is in good condition and the problem is a seal, cartridge, or O-ring. Replacement tends to make sense when:

• The finish is peeling, pitted, or corroded, or the body is cracked
• Replacement parts are discontinued or hard to find
• The repair cost approaches the cost of a new faucet
• The faucet has been repaired repeatedly
• You want a feature the old faucet lacks, such as a pull-down sprayer or a touchless valve

The reasoning is similar to our guide on water heater repair vs. replacement: compare the cost and remaining life of the old unit against a new one, instead of assuming either path is always cheaper.

Preventing Faucet Leaks

• Operate your shutoff valves once or twice a year so they don’t seize.
• Clean aerators periodically, more often if you notice mineral deposits.
• Look under the sink regularly. A quick glance and a touch of the supply lines catches slow leaks early.
• Avoid over-tightening fittings and handles, which can crush seals.
• Replace aging supply lines according to manufacturer guidance.
• Add faucet and under-sink checks to your routine inspections.

The Bottom Line

Most dripping kitchen faucets come down to a worn cartridge, washer, or O-ring, and most homeowners can handle those repairs with the water shut off and the right part. The more important question is where the water is actually going. A drip in the sink is a nuisance. A slow leak in the cabinet is a hidden problem that damages materials and invites mold. Locate the source first, fix what’s within your comfort level, and bring in a professional when the valves, the cabinet, or the faucet body itself are involved.