How to Replace a Kitchen Faucet
Updated February 20, 2026
Swap out an old kitchen faucet in about an hour. Covers single-hole and three-hole installations, supply line connections, and leak testing.
Overview
Replacing a kitchen faucet is one of the most impactful DIY upgrades you can do. A new faucet changes the look of the whole kitchen and fixes drips, low flow, and worn-out handles in one shot. The job takes about an hour. The hardest part is not the plumbing -- it is working in the cramped space under the sink. A basin wrench makes all the difference. Match your new faucet to your sink's hole configuration (single-hole, three-hole, or four-hole) before buying.
What You'll Need
Safety First
- Turn off both hot and cold shut-off valves under the sink before disconnecting anything. Open the faucet to relieve remaining pressure.
- Place a bucket under the connections. Water will drain from the supply lines and faucet body when you disconnect.
Step-by-Step Instructions
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Turn Off Water and Disconnect Supply Lines
Shut off both hot and cold valves under the sink. Open the faucet to drain pressure and remaining water. Place a bucket under the supply connections. Use an adjustable wrench to disconnect the supply lines from the shut-off valves or from the faucet tailpieces -- whichever is easier to access. Let them drain into the bucket.
Tip: If your shut-off valves are old gate valves that do not fully close, shut off the main water supply. This is also a good time to replace those valves with quarter-turn ball valves while the water is off. -
Remove the Old Faucet
From under the sink, remove the mounting nuts holding the faucet to the sink deck. A basin wrench is essential here -- it reaches up behind the sink where your hands and regular wrenches cannot. Turn counterclockwise to loosen. If the nuts are corroded, spray with penetrating oil and wait 10 minutes. Once the nuts are off, lift the old faucet straight up from the top. Scrape old putty or caulk off the sink deck with a putty knife. Clean the surface.
Tip: Take a photo of the old connections before disconnecting. If anything goes wrong with the new install, you have a reference for how it was set up. -
Prep and Set the New Faucet
Read the new faucet's instructions -- they vary by brand. Most include a rubber gasket or deck plate that goes between the faucet base and the sink. If no gasket is provided, apply a bead of plumber's putty around the base. Feed the faucet supply lines and mounting hardware down through the sink holes from the top. Check alignment before tightening.
Tip: Single-hole faucets on a three-hole sink: most come with a deck plate that covers the extra holes. If you want a cleaner look without the plate, use sink hole covers ($3-5) for the unused holes. -
Secure the Faucet from Below
From under the sink, hand-thread the mounting nuts onto the faucet studs. Snug them with a basin wrench or the included tightening tool. Do not overtighten -- you can crack the sink deck (especially on composite or porcelain sinks). The faucet should sit flat and not rotate when you push it from above. Check alignment one more time from the top.
Tip: Have someone hold the faucet in position from above while you tighten from below. Prevents it from spinning or shifting. -
Connect Supply Lines
Connect the hot and cold supply lines. New faucets usually come with braided stainless steel supply lines pre-attached. Connect these to the shut-off valves -- hand-tight plus a quarter turn with a wrench. If the pre-attached lines do not reach, buy new braided supply lines of the correct length. Hot on the left, cold on the right (standard convention).
Tip: Never reuse old supply lines. Braided stainless lines are $5-8 each and are cheap insurance against a flood. Old rubber or chrome lines crack and fail without warning. -
Connect the Sprayer (If Applicable)
Pull-down and pull-out faucets: the spray hose routes through the faucet body and connects underneath with a quick-connect fitting or threaded coupling. Connect per the manufacturer's instructions. Clip the counterweight to the hose (included with most faucets) -- this retracts the sprayer when you release it.
Tip: Run the sprayer hose through the faucet body and pull it out to full extension before connecting underneath. Make sure it does not catch on anything under the sink. -
Turn On Water and Test
Remove the faucet aerator (unscrew the tip). Turn on both shut-off valves slowly. Let water run for 30 seconds to flush debris from the new faucet and supply lines. Check every connection under the sink for leaks -- run your hand along each joint. Test hot and cold. Test the sprayer. Reinstall the aerator. Check for leaks again after 10 minutes.
Tip: Removing the aerator before the first run is important. Manufacturing debris and pipe particles can clog the aerator screen immediately. Flush first, then install.
Pro Tips
- Buy the faucet first, then verify it fits your sink before removing the old one. Check hole count, hole spacing (4 inches standard, 8 inches widespread), and reach.
- A basin wrench ($15-25) is the one tool that makes this job possible without cursing. The right-angle jaw reaches mounting nuts in spaces your hands cannot.
- If your shut-off valves are older than 10 years, replace them while you have the water off. A valve failure during a faucet swap means no water to the kitchen until the main is off and the valve is replaced.
- LED-lit flashlight or headlamp for under-sink work. You need both hands free and good visibility in a dark cabinet.
- Silicone-based plumber's putty instead of traditional putty if you have a granite or marble sink. Traditional putty can stain natural stone.
When to Call a Pro
Call a plumber if your shut-off valves will not close and need replacement, if your supply lines are galvanized steel and need to be converted to flexible, if the sink holes do not match the new faucet and need drilling, or if the old mounting nuts are corroded solid and you cannot break them free.