How Do You Replace A Kitchen Faucet: DIY Guide

Yes, you can replace a kitchen faucet yourself! Replacing a kitchen faucet is a common home repair that most handy homeowners can tackle over a weekend. This kitchen faucet replacement guide walks you through every part of installing a new kitchen faucet, from shutting off the water to testing your work. If you are currently fixing a leaking kitchen faucet or just want a kitchen sink faucet upgrade, this guide offers clear steps to replace a sink faucet.

Preparing for Your DIY Kitchen Faucet Change

Before you grab your tools, you need a solid plan. Good preparation makes the whole job faster and much smoother. A successful DIY kitchen faucet change starts here.

Deciphering Your Current Setup

Look under your sink. How many holes does your sink deck have? Your new faucet must match your sink configuration.

Single-Hole Faucet: Only one hole is needed.
Centerset Faucet (4-inch spread): Uses three holes close together.
Widespread Faucet (8-inch spread): Uses three separate holes.

If your new faucet needs fewer holes than your sink currently has, you might need an escutcheon plate (a deck plate) to cover the extra holes. If you need more holes, you might have to drill new ones—a task best left to professionals if you have granite or fireclay sinks.

Selecting Your New Faucet

Choose a faucet that fits your sink holes. Also, think about features: pull-down sprayers, soap dispensers, or motion sensors. Make sure the spout reach fits your sink basin well.

Gathering the Best Tools for Faucet Replacement

You cannot do this job without the right gear. Having the best tools for faucet replacement ready saves time and frustration when working in tight spaces.

Tool Name	Purpose	Why It Matters
Basin Wrench	Reaching nuts up behind the sink basin.	Essential for most under-sink work.
Adjustable Wrench or Pliers	Tightening supply line connections.	For standard nuts and fittings.
Screwdrivers (Phillips and Flathead)	Removing mounting screws or handles.	Needed for older or specific models.
Safety Glasses	Protecting your eyes from falling debris.	Safety first, especially when looking up.
Utility Knife or Putty Knife	Scraping off old plumber’s putty or caulk.	For a clean seal with the new faucet.
Bucket and Towels	Catching drips and spills.	Keeps your cabinet dry.
Flashlight or Headlamp	Lighting up the dark space under the sink.	Essential for seeing what you are doing.
Plumber’s Putty or Silicone Caulk	Creating a watertight seal between the faucet base and the sink.	Prevents leaks from the top edge.

Step-by-Step Guide to Faucet Removal

The first big part of plumbing under sink faucet replacement is removing the old unit. This often takes longer than installing the new one!

Turning Off the Water Supply

This is the most important first step.

Locate the shut-off valves under the sink. These control hot and cold water leading to the faucet.
Turn both valves fully clockwise until they stop.
Turn on the old faucet handles (both hot and cold) above the sink. Let the water run until it stops completely. This relieves the pressure in the lines.

If you cannot find or turn these local shut-off valves, you must turn off the main water supply to your entire house.

Clearing Out the Workspace

Move everything out from under the sink cabinet. Place your bucket and towels directly beneath the faucet connections. You will be working in a cramped space, so make sure you have good light.

Disconnecting Old Kitchen Faucet Supply Lines

This is where you disconnect old kitchen faucet supply lines.

Use your adjustable wrench or pliers. Hold the shut-off valve steady with one hand.
Loosen the compression nut connecting the flexible supply line to the shut-off valve. Be ready for a small amount of residual water to drip out.
Repeat this for the other supply line.
If your faucet has its own integrated supply lines, carefully disconnect them from the angle stops (shut-off valves).

Detaching the Old Faucet Mounting Hardware

This is often the trickiest part, especially with older faucets. You need to access the mounting nuts or screws holding the faucet body tight against the sink.

Get your basin wrench. Look straight up at the underside of the faucet base. You will see large nuts or mounting brackets.
Place the jaw of the basin wrench around the nut. Turn the nut counter-clockwise to loosen it. This requires effort because corrosion and water deposits can make them stick tight.
If the faucet uses screws instead of nuts, use a screwdriver to loosen them.
Once all hardware is loose, gently lift the old faucet straight up and out from the top of the sink.
Clean the area where the old faucet sat. Scrape away any old putty, caulk, or mineral deposits using your putty knife. A clean surface ensures a tight seal for the new unit.

Installing the New Kitchen Faucet

Now that the path is clear, you are ready to connect new kitchen faucet components. Read your new faucet’s manual carefully, as assembly steps vary widely between brands.

Preparing the New Faucet Base

Many modern faucets come partially assembled. You might need to install the sprayer hose or connect the water lines before setting the faucet in place.

Apply Sealant: If your faucet model does not come with a rubber gasket for the base, apply a thin bead of plumber’s putty or silicone caulk around the bottom edge of the faucet base (or the escutcheon plate, if using one). This prevents water from seeping under the base into your countertop or cabinet.
Feed Lines Through Holes: Carefully feed all hoses and threaded shanks (the metal posts that go through the sink holes) down through the mounting holes in the sink deck.

Securing the Faucet to the Sink

This step mimics the removal process in reverse.

From underneath the sink, slide the rubber gasket and the metal mounting plate (if provided) onto the faucet shanks.
Hand-tighten the mounting nuts onto the shanks.
Adjust the faucet body above the sink to ensure it is perfectly straight and centered.
Use your basin wrench or appropriate tool to tighten the mounting nuts firmly. Do not overtighten, as this can crack delicate sink materials, but make sure the faucet doesn’t wiggle.

Connecting the Water Supply Lines

This is the final plumbing connection phase. Use your adjustable wrench for these connections.

Attach Supply Lines to Faucet (if necessary): If your new faucet did not come with supply lines already attached, screw the flexible hot and cold lines onto the faucet inlets. Hand-tighten first, then use the wrench for a quarter turn.
Connect to Shut-Off Valves: Connect the other ends of the supply lines to the corresponding hot (usually left) and cold (usually right) shut-off valves. Again, hand-tighten, then finish with the wrench. Ensure the connection is snug but avoid excessive force.

Installing Sprayer Hoses and Weights (If Applicable)

If your new faucet includes a pull-down or side sprayer:

Connect the sprayer hose to the designated port on the faucet body under the sink.
Attach the small counterweight (usually included) to the loop of the sprayer hose, following the manufacturer’s height recommendations. This weight helps the sprayer retract smoothly back into the spout.

Final Checks and Testing

You have finished the physical plumbing under sink faucet replacement. Now it is time to check your work before cleaning up.

Restoring Water Pressure Slowly

Rushing this step can cause leaks or blow out newly tightened connections.

Make sure the faucet handles above the sink are in the OFF position.
Slowly turn the hot water shut-off valve counter-clockwise to open it. Listen for any immediate sounds of spraying water underneath.
Slowly open the cold water shut-off valve.
If everything seems dry, turn both valves fully open.

Testing the Faucet Operation

Slowly turn on the faucet above the sink to the cold setting. Let it run for a minute. Check for strong flow.
Turn it to the hot setting. Check for flow and temperature.
Cycle the handles several times. Run both hot and cold at full blast.
If you have a sprayer, test it thoroughly.

Inspecting for Leaks (The Critical Check)

This is the moment of truth for any kitchen faucet replacement guide.

Use a dry paper towel or tissue. Wipe around every single connection point you touched: where the supply lines meet the shut-off valves, and where they meet the faucet body.
Check the mounting nuts under the sink.
Wait about 15 minutes. Check the towel again. If you see any dampness, immediately turn off the water supply valves and tighten that specific connection slightly more. Re-test.

Advanced Tips for Smooth Installation

Some situations require extra care during your DIY kitchen faucet change.

Dealing with Corrosion and Stuck Nuts

Corroded brass or galvanized nuts can seize up. If a standard wrench won’t budge them, try these methods before applying extreme force:

Penetrating Oil: Spray a quality penetrating oil (like WD-40 or PB Blaster) on the stuck nut threads. Let it soak for 30 minutes or even overnight.
Heat (Use Extreme Caution): A small torch can sometimes loosen a stuck metal nut by causing expansion. Warning: Never use heat near plastic supply lines, old PVC pipes, or if you smell gas. This is risky and requires good ventilation.

Using a Plumber’s Putty Alternative

Modern solid-surface countertops (like quartz or granite) often advise against using traditional plumber’s putty because its oils can stain the stone over time.

Silicone Caulk: Use 100% silicone sealant instead. It offers a great, waterproof seal and will not stain the stone. Apply it thinly before seating the faucet base.

Replacing Supply Lines Even If They Look Fine

If you are performing a major kitchen sink faucet upgrade, it is often wise to replace the flexible supply lines too. Old rubber hoses can degrade internally, leading to sudden bursts later on. Modern braided stainless steel lines are very reliable.

When to Call a Professional

While this is a DIY guide, know your limits. You should call a plumber if:

Your shut-off valves are old, corroded, or do not turn off the water completely.
Your sink base requires drilling new holes in hard material (like thick stone).
You find significant water damage or mold under the sink during the removal process.
You cannot stop a leak after retightening the connections multiple times.

FAQ: Common Kitchen Faucet Replacement Questions

What size basin wrench do I need for kitchen faucet replacement?

Most modern faucets use fittings that require a basin wrench with a jaw opening between 1/2 inch and 1 1/4 inches. A good universal or telescoping basin wrench will usually cover the sizes needed for plumbing under sink faucet replacement.

How long does it typically take to replace a kitchen faucet?

For an experienced DIYer with the right tools, the job can take as little as one hour. For a first-timer, especially when having to disconnect old kitchen faucet hardware that is stuck, allow three to four hours. This accounts for cleaning up the old workspace and patiently testing for leaks.

Can I reuse my old water supply lines when installing a new kitchen faucet?

It is strongly advised not to reuse old supply lines if they are over five years old, cracked, or heavily corroded. While reusing them is possible if they look perfect, replacing them is cheap insurance against future fixing a leaking kitchen faucet emergencies.

My new faucet won’t sit flat; what should I do?

If the new faucet base is rocking, you likely have debris or an uneven surface under the sink deck, or you have not fully tightened the mounting nuts. If the surface is clean and the nuts are tight, check the faucet’s mounting plate. Sometimes, the rubber gasket is folded or misplaced, preventing a flush fit.

Do I need plumber’s putty or silicone caulk for installing a new kitchen faucet?

If you have a composite, stainless steel, or enameled cast iron sink, plumber’s putty is generally fine. If you have a natural stone countertop (granite, marble, quartz), you must use 100% silicone caulk to avoid staining the stone. Many newer faucets include a rubber gasket, eliminating the need for putty or caulk altogether.