How to Fix a Leaky Kitchen Faucet (Spout, Handle, Base & Under Sink)

Quick answer

A leaky kitchen faucet is usually a worn seal, cartridge, mounting nut, or supply connection—not something fixed by forcing the handle tighter. Shut off hot and cold under the sink, find where it drips (spout, handle, base, or under the sink), match your faucet type, then replace the matching part. Call a plumber for wall leaks, failed shutoffs, or cabinet damage.

Quick facts: Time ~30–45 min · Difficulty: Easy · Parts ~$8–$35 (O-ring/washer kit $8–$15, brand-name cartridge $15–$35) · Tools: adjustable or basin wrench, screwdrivers, Allen keys.

Most kitchen faucet leak repair starts with location, not tools. A dripping or leaking kitchen faucet wastes water and can soak cabinets if drips run under the sink unnoticed. Compression, cartridge, ball, and ceramic-disk faucets use different parts—so identify your style (or brand/model) before you buy seals.

Before you remove parts, confirm you can shut off water at the angle stops under the sink. If those valves are stuck or missing, locate your main water shutoff first. Inventory other stops with the appliance shutoff valves guide. Weak spray with the handle on is often an aerator or pressure issue—not a seal leak. For broader plumbing boundaries, see when to call a plumber vs DIY.

How to Find Where the Kitchen Faucet Is Leaking

Dry the spout, handle, deck, and cabinet floor with a towel. Run water briefly (or leave the faucet off if it drips alone), then watch where moisture returns.

Take a photo before disassembly. If water appears on the wall or floor with no clear faucet connection, stop.

Kitchen Faucet Leaking From the Spout

A drip from the spout tip when the handle is off usually means internal seals—not the aerator alone (though a clogged aerator can splash oddly when water is on).

1. Shut off water and relieve pressure by opening the faucet.
2. Remove the handle and access the cartridge or stem for your faucet type.
3. Replace the cartridge, seat washer, or O-rings that match your model—bring the old part to the store when possible.
4. Reassemble without forcing plastic retaining clips.

If water only sprays sideways when the faucet is on, unscrew the aerator, clean the screen, and replace a cracked gasket—or follow how to clean a faucet aerator for the full soak-and-reassemble steps.

Kitchen Faucet Leaking From the Handle

Water tracking down the handle or pooling at the handle base points to packing, an O-ring under the handle, or a failing cartridge seal.

• Note handle orientation before removal (hot/cold or up/down).
• Replace the O-ring or packing nut parts listed for your faucet—not a random washer.
• Avoid pipe wrenches on finished nuts; they round flats and scratch finishes.

Overtightening the handle will not stop seal wear and can crack cartridges.

Kitchen Faucet Leaking at the Base

Water pooling around the faucet body or sink deck—not at the spout tip—usually means mounting or connection issues:

• Mounting nuts — Under the sink, nuts or a bracket hold the body to the deck. Looseness lets the body shift and break the seal. Hand-tighten, then snug a quarter turn with a basin wrench. Do not overtighten thin sinks.
• O-rings under the body — Many faucets use a deck gasket or O-ring. If the body lifts or mineral trails run from the base, replace with an exact match.
• Sprayer hose — Pull-down/pull-out models have two leak points most guides gloss over: the quick-connect clip where the hose meets the supply under the sink, and the weight hose (the sliding counterweight can chafe the hose over time). Either can drip and look like a deck leak. Dry everything, run water, and trace the start of the drip.
• Not a supply-line leak — Drips on braided lines or shutoff stems are supply problems. Tightening faucet mounting nuts will not fix them. If shutoffs fail when you operate them, see when to call a plumber vs DIY.

Kitchen Faucet Leaking Under the Sink

A wet cabinet floor does not always mean the faucet seals failed.

1. Dry everything, then isolate: drip at supply nuts, shutoff stems, sprayer hose, or drain/P-trap.
2. Supply nuts often need a gentle quarter-turn—do not crush the ferrule on braided lines.
3. A shutoff that drips at the stem may need packing adjustment or replacement (old valves can fail when turned).
4. Slow drains with standing water under the sink may be the trap—see how to clean a P-trap—not faucet repair.

Kitchen Faucet Leaking From the Supply Line

Know every stop under the sink—see appliance shutoff valves—before you assume the faucet body is the only leak path.

O-Rings, Cartridges, and Seals

Most spout and handle leaks are worn internals, not a “loose handle.”

Do not force mismatched cartridges. If threads or seats are chewed up, repair may not hold—replace the faucet or call a plumber.

Mounting Hardware

Base and deck leaks often track back to how the faucet is fastened—not to spout seals.

• Mounting nuts / bracket — Under the deck; looseness lets the body rock and break the gasket seal. Hand-tighten, then a light snug with a basin wrench.
• Deck gasket / putty — Seals the body to the sink. Replace if the faucet lifts or mineral trails run from the base.
• Escutcheon / deck plate — Can hide a deck leak on multi-hole sinks; dry and re-trace before assuming a spout problem.
• Sprayer quick-connect — Hose clips under the sink can drip onto the cabinet floor and look like a mounting leak.

Overtightening thin stainless sinks or plastic brackets cracks them—snug is enough.

How to Repair the Leak (Step by Step)

1. Shut off water — Clockwise on hot and cold under the sink. Open the faucet to drain pressure.
2. Confirm the leak path — Dry the area; check spout, handle, base, supply nuts, and sprayer connections.
3. Identify faucet type — See the table below; note brand/model on the body or paperwork.
4. Remove the handle — Set screw often under a decorative cap.
5. Access the valve body — Remove retaining clip or nut; pull cartridge or stem.
6. Replace matching parts — Cartridge, washers, or O-rings that match your model. Clean mineral buildup carefully on non-plated surfaces if needed.
7. Reassemble without overtightening — Snug mounting and handle screws; overtightening strips threads and cracks cartridges.
8. Restore water slowly — Check spout, handle, base, and supply connections for several minutes.

Identify your faucet type

Hardware stores stock common cartridges if you bring the old part. Avoid mixing incompatible models.

Cartridge brands most people actually own

Most US kitchen sinks have a single-handle cartridge faucet — Moen, Delta, and similar styles are the most common. Cartridges are not interchangeable between brands (or even between product lines of the same brand), so matching matters more than the price tag: a $22 brand-compatible cartridge that fits beats a $12 "universal" one that doesn't.

You don't need to memorize model numbers. Pull the old cartridge, take it to the store, and match it side by side — the "bring the old part" rule in the parts list above is the whole strategy.

Parts You May Need

Tools needed

• Adjustable wrench or basin wrench
• Phillips and flathead screwdrivers
• Allen keys (some handles)
• Flashlight
• Bucket and towels
• Replacement cartridge, washers, or O-rings (match your model)
• Plumber's grease (silicone-based, if recommended for your parts)

Most repairs need only basic hand tools—see our beginner DIY tool kit if you are stocking up.

Buy parts after you know the faucet type or have the old cartridge in hand. “Universal” kits are not always universal.

Signs of cabinet or hidden damage

• Soft, stained, or buckled cabinet floor
• Mold smell under sink
• Water trails on the back wall

Fix the leak source first, then dry the cabinet. Persistent wetness after faucet repair suggests another path—or prior damage.

When to replace the whole faucet

• Body is pitted or cracked
• Multiple repairs fail within months
• Parts discontinued for your model
• Finish damage with internal corrosion

Like-for-like swaps are often DIY if shutoffs work—still within plumber vs DIY judgment if you're unsure.

Common mistakes

• Overtightening handles (doesn't fix seal wear)
• Mixing incompatible cartridge models
• Forgetting to turn off water
• Ignoring supply-line drips while chasing a spout drip
• Using a pipe wrench on finished faucet nuts

DIY vs Plumber

Full boundaries: when to call a plumber vs DIY.

Bottom line

Locate the leak first, shut off water, match your faucet type, replace worn seals or cartridges, and test every connection. A leaking kitchen faucet is often a homeowner fix; wall leaks, failed shutoffs, and repeated failures are signals to stop and get professional help. If the same sink drains slowly, see how to clean the P-trap.