How to Replace a Sink Faucet: Step-by-Step Guide

The Short Answer: You Can Replace a Sink Faucet Yourself in 1–2 Hours

Replacing a sink faucet — whether it's a kitchen spigot that's been dripping for months or a bathroom fixture that's completely lost pressure — is one of the most manageable home plumbing jobs for a DIYer. You don't need a plumber's license, and in most cases you don't even need to shut off the water at the main valve. With the right tools, a replacement faucet, and about 90 minutes of focused work, you can pull out the old unit and have the new one running clean and leak-free.

The process breaks down into four main phases: turning off the water supply, disconnecting the old faucet and supply lines, installing the new faucet body and hardware, and reconnecting the water lines before testing for leaks. Each phase has a few details worth knowing — wrong wrench size, over-tightened connections, or skipping the plumber's tape can cost you a second trip under the sink — so this guide walks through every step in full.

Tools and Materials You'll Need Before You Start

Gathering everything before crawling under the cabinet saves real time. A half-finished job is far more frustrating when you have to make a hardware-store run mid-way through. Below is a complete list of what most faucet replacements require:

• Adjustable wrench or basin wrench (a basin wrench is nearly essential for deep, hard-to-reach mounting nuts)
• Channel-lock pliers
• Plumber's tape (PTFE tape, also called thread-seal tape)
• Replacement supply lines (typically 12-inch or 20-inch braided stainless steel, sold separately or as a bundle)
• Bucket or towel to catch residual water
• Flashlight or headlamp
• Putty knife or plastic scraper (to remove old plumber's putty or caulk from the sink deck)
• Silicone caulk or plumber's putty (check manufacturer instructions — many modern faucets specify one or the other)
• Pen and notepad or phone camera (to document existing connections before disassembly)

The basin wrench deserves special mention. It's a long-handled tool with a swiveling jaw designed specifically to reach up into the narrow space between the sink basin and the cabinet floor to grip mounting nuts. Without it, removing the old faucet from a deep sink installation can take 45 minutes or more; with one, the job typically takes under 10 minutes. They cost $15–$30 at most hardware stores and are worth every dollar.

Choosing the Right Replacement Faucet

Before purchasing a replacement, count the number of holes in your sink deck. Most kitchen sinks have either a single hole (for a single-handle faucet) or three holes spaced 4 inches apart (for a two-handle faucet set). Bathroom sinks commonly follow a 4-inch or 8-inch center spread. Buying a faucet that doesn't match your sink's hole configuration will require either a different sink or an escutcheon plate to cover unused holes.

Also check the faucet's spout reach and height against your sink basin depth. A kitchen spigot with a 10-inch spout height may look dramatic in a showroom but be completely impractical in a low-clearance cabinet installation under a window. Measure your existing faucet's spout height and reach before ordering online.

Step-by-Step: How to Remove the Old Faucet

Removal is typically the harder half of the job, especially if the faucet has been in place for more than five years. Mineral deposits and corrosion can bond supply line connections and mounting nuts to the point where they feel immovable. Take your time here; forcing connections risks cracking supply valves or damaging the sink deck.

Shut Off the Water Supply

Look under the sink for the two shutoff valves — one for hot water (usually on the left) and one for cold (right). Turn them clockwise until they stop. If the valves are older gate-style valves that don't shut completely, or if there are no under-sink shutoffs, turn off the main water supply to the house instead.

After closing the valves, open the faucet handles to release pressure and drain any remaining water from the lines. Place a towel or small bucket under the supply line connections — there will be residual water even after this step.

Disconnect the Supply Lines

Use an adjustable wrench to loosen the nuts connecting the supply lines to both the shutoff valves and the faucet inlets. Turn counterclockwise. If the line turns with the nut (common with older braided lines), hold the line steady with channel-lock pliers while you turn the nut.

Replace supply lines every time you replace a faucet — they're inexpensive ($8–$15 for a quality braided stainless pair) and a common source of under-sink leaks. There's no reason to reuse a line that's already five or ten years old.

Remove the Mounting Hardware

This is where the basin wrench earns its keep. The mounting nuts — usually one or two large plastic or metal nuts threaded onto the faucet shanks from below — are positioned in a tight space between the sink basin and the cabinet floor. Insert the basin wrench, position the jaw around the nut, and rotate counterclockwise. On a faucet with two handles, each handle assembly may have its own separate nut.

If a nut won't break loose, spray penetrating oil (like PB Blaster) onto the threads, wait 10–15 minutes, and try again. A stubborn nut is far better addressed with patience and penetrating oil than with excessive force that cracks a porcelain sink deck.

Lift Out the Old Faucet and Clean the Sink Deck

Once the nuts are off, the faucet body lifts straight up from above the sink. You'll likely find a ring of old plumber's putty, silicone, or mineral scale where the base plate sat against the sink. Scrape this away thoroughly with a putty knife and clean the area with rubbing alcohol or a mild abrasive cleaner. A clean, flat seating surface is critical — any residual buildup under the new faucet's base plate can create gaps that allow water to seep under and eventually rot the cabinet below.

Step-by-Step: Installing the New Faucet

Read the manufacturer's instructions that come with your new faucet before starting installation — even if you've done this job before. Faucet hardware varies significantly between brands. Some require you to assemble the spigot body before dropping it into the sink; others go in as a single pre-assembled unit. Some specify plumber's putty for the base seal; others require silicone and explicitly warn against putty, which can crack certain composite sink materials.

Apply the Base Seal

If the manufacturer recommends plumber's putty: roll a rope of putty about ½ inch thick, press it around the underside of the faucet's base plate, and lower the faucet into the mounting holes. The putty will compress slightly as you tighten the mounting hardware from below, creating a watertight seal. Trim any squeeze-out from the edges with a putty knife after tightening.

If the manufacturer recommends silicone: run a thin, continuous bead around the base plate's underside perimeter, press the faucet into position, and allow it to set according to the silicone's cure time (typically 24 hours for a full waterproof cure, though 1–2 hours is usually sufficient before turning the water back on).

Many modern faucets include a pre-formed rubber gasket that eliminates the need for putty or caulk entirely. If your faucet includes a gasket, simply place it on the bottom of the base plate before lowering the unit into the sink holes.

Secure the Mounting Hardware from Below

Thread the mounting nut (or nuts) onto the faucet shank(s) from below the sink and hand-tighten first to confirm the faucet is sitting level and centered over the holes. Then use your basin wrench to tighten — snug, but not so tight that you crack the sink deck. Over-tightening is one of the most common installation mistakes; a cracked porcelain sink costs far more to replace than any faucet.

The general rule: hand tight plus about a quarter to half turn with the wrench is sufficient for plastic mounting nuts. Metal nuts can take slightly more torque, but stop as soon as resistance feels firm — not with continued force.

Connect the Supply Lines

New braided stainless supply lines typically include rubber washers pre-installed inside each end fitting — these create the watertight seal at the connection points, so you do not need PTFE tape on these connections. Thread each line onto its corresponding faucet inlet (hot to the hot port, cold to the cold) hand-tight, then snug with an adjustable wrench — again, about a quarter turn past hand-tight.

Attach the other end of each supply line to its corresponding shutoff valve. Check that the lines are not kinked or twisted — a kinked supply line reduces water flow and can eventually cause the line to fail. If a line seems too long and wants to kink, use a longer or shorter line rather than forcing a bend.

Install the Drain Assembly (If Applicable)

Many bathroom faucet kits include a pop-up drain assembly. If yours does, remove the old drain stopper and pivot rod, and install the new assembly according to the instructions. The pivot rod connects the lift rod (behind the spigot) to the stopper in the drain, and its horizontal position in the drain body determines how far the stopper opens and closes. This is adjustable — test it after installation and adjust the clevis strap clip position if the stopper doesn't open or close fully.

Turning the Water Back On and Checking for Leaks

This step is where patience pays off. Rushing to declare the job done before a proper leak check is how minor drips become water-damaged cabinets.

1. Slowly open the cold water shutoff valve first (counterclockwise) — turn it gradually rather than all at once. Watch the supply line connections for any immediate dripping.
2. Once the cold line is fully open with no drips, open the hot water shutoff valve the same way.
3. Turn on the faucet and let water run for 30–60 seconds to flush any debris or air from the lines. The flow may sputter briefly — this is normal.
4. Check under the sink carefully — look at both ends of each supply line, around the faucet base where it meets the sink deck, and around the shutoff valves themselves. Use a dry paper towel to dab each connection; even slow seeps will show up immediately on a dry surface.
5. If you see a drip at a supply line connection, tighten it an additional quarter turn. If leaking persists after tightening, shut the water off, disconnect the line, and check that the rubber washer is seated properly.

Check again 24 hours after installation — some slow seeps don't appear until the supply lines have been under full pressure for a full day. A brief inspection the following morning is good practice on any plumbing job.

Common Problems and How to Handle Them

Even a straightforward faucet replacement can hit unexpected snags. Here are the most common issues and what to do about each one:

The Shutoff Valves Won't Close Completely

Older homes often have gate valves under sinks that have partially seized from years of non-use. If you turn the valve fully clockwise but still see a trickle of water from the faucet, the valve is failing. You have two options: turn off the main water supply and replace the shutoff valve while you're already doing the faucet (recommended, since it's a similar level of work), or use the main shutoff for this project and schedule the valve replacement separately.

Replacing old gate valves with quarter-turn ball valves is a significant upgrade — ball valves seal completely and last far longer, and they cost around $8–$12 each at the hardware store.

The Old Spigot Mounting Nut Is Corroded Solid

If penetrating oil and patience don't free the nut, a hacksaw blade (used by hand without the frame) can cut through a plastic nut in a confined space. For metal nuts, a reciprocating saw with a metal-cutting blade or an oscillating tool works well — just protect the sink surface from blade contact. Once the nut is cut, the old faucet will lift free and you can start fresh with the installation.

Low Water Pressure After Installation

If the new faucet runs noticeably weaker than expected, check three things in order. First, confirm both shutoff valves are fully open — sometimes they get closed only partway in the process. Second, check the supply lines for kinks. Third, locate the aerator at the tip of the spout (the small screen fitting that screws onto the end of the spout). On a brand-new faucet, debris from installation can lodge in the aerator screen. Unscrew it, rinse it, and reinstall.

If none of those explain the issue, some new faucets — particularly pull-down kitchen models — have flow restrictors inside the spout body designed to reduce water use. These can sometimes be removed if higher flow is preferred; check the manufacturer's instructions.

Water Leaks Around the Spigot Base

A leak between the faucet base and the sink deck usually means the mounting hardware isn't tight enough, or the putty or silicone seal didn't form properly. Tighten the mounting nuts by a quarter turn and check again. If the problem persists, you'll need to remove the faucet, clean the sink deck and base plate completely, and apply a fresh seal.

Kitchen Faucet vs. Bathroom Faucet: Key Differences in the Replacement Process

While the core process is the same, kitchen and bathroom faucet replacements have a few differences worth knowing before you start.

Kitchen Faucets

Kitchen sink spigots are almost always heavier and more complex than bathroom models. Pull-down and pull-out faucets have a weighted hose that loops under the sink — make sure the counterweight is properly installed on the hose or the spray head will sag rather than retracting. Deck-mounted kitchen faucets also frequently have a separate side sprayer or soap dispenser hole; if your replacement doesn't use all the holes in a multi-hole sink, cover the unused holes with decorative hole covers (around $10–$20 each at plumbing suppliers).

Kitchen faucets also deal with heavier use and more food debris. Braided stainless supply lines are strongly recommended for kitchen spigots over plain chrome lines, as braided lines resist kinking and are far more durable under high-use conditions.

Bathroom Faucets

Bathroom faucet replacements usually include replacing the drain assembly, which adds one extra step. Bathroom installations also deal more frequently with tight cabinet spaces and smaller shutoff valves, so a compact adjustable wrench and a good headlamp are helpful.

Widespread bathroom faucets — where the handles and spout body are all mounted separately through individual holes — are slightly more involved because each component is installed and connected independently. Budget an extra 20–30 minutes for widespread faucet installation compared to a centerset (single base plate) model.

When to Replace vs. Repair a Faucet

Not every faucet problem requires a full replacement. A dripping faucet is usually a worn cartridge or O-ring — a $10–$25 repair part that takes under an hour to swap out. A wobbly handle often just needs the set screw tightened. But full replacement makes more sense in several situations:

• The faucet body itself is cracked or corroded — no repair addresses structural damage to the spigot housing.
• The faucet is more than 15–20 years old and has already had multiple repairs. At some point, the cumulative cost of cartridges, seats, and O-rings exceeds a new unit.
• Replacement parts for the existing model are no longer available (common with discontinued brands or budget fixtures).
• You want to update the finish (chrome to brushed nickel, for example) to match other bathroom or kitchen hardware — finish can't be painted on effectively, so replacement is the only real option.
• The faucet is causing persistent low pressure issues even after aerator cleaning and cartridge replacement, suggesting internal valve body wear.

A quality mid-range faucet from a reputable brand — Moen, Delta, Kohler, American Standard — typically costs $80–$250 and carries a lifetime warranty on internal components. That's a compelling value compared to repeated repair calls on an aging budget spigot.

Frequently Asked Questions About Faucet Replacement

Do I need a plumber to replace a kitchen or bathroom faucet?

In most cases, no. Faucet replacement is considered a basic DIY plumbing task in most jurisdictions and doesn't require a permit or licensed plumber. The exception is if the replacement uncovers other plumbing issues — a corroded supply stub-out, for example, or water damage from a long-running slow leak behind the wall. In those cases, a licensed plumber is the right call. Plumbers charge $75–$150 per hour on average, and a straightforward spigot installation typically takes them 30–45 minutes if you supply the fixture.

How long does a new faucet typically last?

A mid-to-high quality faucet from a major brand should last 15–20 years with normal use. Budget faucets under $50 may need cartridge replacement within 3–5 years. Water quality is a significant factor — hard water with high mineral content accelerates wear on internal valve components and can clog aerators. In hard-water areas, using a faucet-mounted or under-sink water filter can meaningfully extend fixture life.

Can I replace a two-handle faucet with a single-handle model?

Yes, provided your sink has the right hole configuration. A standard kitchen sink with three holes on an 8-inch spread can accept a single-handle faucet — the two outer holes are simply covered with the included deck plate or escutcheon. The reverse is also possible: switching from a single-hole to a three-hole configuration requires drilling additional holes in the sink deck, which is feasible for stainless steel sinks using a step drill bit but not practical for porcelain or cast-iron sinks.

Does replacing a faucet increase home value?

Direct value increase from a single faucet replacement is modest, but updated fixtures contribute to the overall impression of a well-maintained home. Real estate professionals consistently report that kitchens and bathrooms drive buyer perception more than other areas. Replacing a visibly outdated or stained spigot with a modern brushed nickel or matte black model — combined with matching hardware — can meaningfully improve how buyers perceive a bathroom without a full remodel. As a component of a broader kitchen or bath update, fixture upgrades are considered high-ROI improvements.