How to Replace a Kitchen Faucet in 7 Steps (+ Common Mistakes)
Replacing a kitchen faucet yourself costs $50–$315 in materials and takes about 1–2 hours. Hiring a plumber runs $150–$300 in labor alone, plus a 50–100% markup on the faucet. The job requires four basic tools, and the most common mistake—over-tightening supply lines—is completely avoidable if you know what to watch for.
This guide walks through the full process, from shutting off water to testing for leaks. I’ve done this in a 1970s house with corroded shut-off valves and in rentals with no shut-off valves at all. Both scenarios are covered here.
What you’ll need
Tools:
- Basin wrench ($8–$15—the one specialty tool you must have)
- Adjustable wrench (two if possible)
- Putty knife
- Bucket
- Towels or drop cloth
- Headlamp or flashlight
Materials:
- New kitchen faucet ($40–$300; see recommendations below)
- Braided stainless steel supply lines (often included; if not, $5–$10 per pair)
- Silicone caulk (if faucet requires it; $3–$5)
Prerequisites:
- Access to shut-off valves under the sink (or willingness to shut off the main water supply)
- Sink deck in good condition (no cracks around the faucet hole)
Before you start
Locate the shut-off valves under your sink—one for hot water, one for cold. They should be on the supply lines coming out of the wall or floor. Turn them both slowly to make sure they work before you start the job.
Stop right here if: The valves are stuck, corroded, leaking when you turn them, or missing entirely. A broken shut-off valve mid-project turns a 1-hour job into an emergency visit and potential water damage. Call a plumber instead. It’s a faster and safer path.
If there are no shut-off valves under the sink, you’ll need to shut off the main water supply to the house. This is doable but adds 20 minutes and affects every fixture while you work.
Step 1: Turn off the water supply
Turn both shut-off valves clockwise until snug. Do not over-tighten—these valves wear out if you muscle them.
Turn on the faucet at the sink and let it run for 10 seconds. If water stops, you’re good. If water keeps flowing, the shut-off valve isn’t working. Shut off the main supply or call a plumber before proceeding.
Place a bucket under the sink to catch remaining water in the lines.
Step 2: Disconnect the supply lines
Using an adjustable wrench, hold the fitting nut (the part attached to the faucet inlet) while turning the connector (the part attached to the supply line) with a second wrench. If you use only one wrench, the fitting will spin and you’ll round off the nut.
Unscrew both hot and cold supply lines. Water will drip—that’s normal. Let it drain into the bucket.
Image: Close-up of two wrenches on supply line connection, showing proper hold-and-turn technique
Step 3: Remove the old faucet
Most faucets are held in place by a mounting nut from underneath the sink. Use the basin wrench to reach it—this tool has a pivoting jaw designed to grip the nut in tight spaces where a regular wrench won’t fit.
Turn counter-clockwise to loosen the nut. Once it’s off, lift the old faucet out from above. There may be caulk or plumber’s putty around the base; use a putty knife to break the seal if it’s stuck.
If your faucet uses a clip or collar instead of a nut, consult the manufacturer’s instructions for removal.
Step 4: Clean the sink deck
Scrape off old caulk, plumber’s putty, and mineral deposits with the putty knife. Wipe the area with a damp cloth. The new faucet needs a clean surface to seal properly.
Step 5: Install the new faucet
Follow the manufacturer’s instructions—faucet designs vary. Most have a rubber gasket that sits between the faucet base and the sink deck, and a mounting nut that threads onto the faucet body from underneath.
Insert the faucet through the holes in the sink deck. Hand-tighten the mounting nut, then use the basin wrench to snug it—but don’t over-tighten. The faucet should be level and centered. Check from above before fully tightening.
Image: New faucet being positioned in sink holes, showing gasket placement
Step 6: Connect the supply lines
Attach the supply lines to the hot and cold inlets on the faucet. Hand-tighten first, then use two wrenches (one holding the fitting, one turning the connector) to tighten until snug. Then turn an additional 1/4 to 1/2 turn. Stop.
Over-tightening is the #1 cause of cracked fittings and leaks. If you see water dripping after you turn the water back on, tighten only 1/8 turn more. Do not muscle it.
Step 7: Turn the water back on and test
Open both shut-off valves slowly by turning them counter-clockwise. Open the faucet and run water for 30 seconds to clear air from the lines.
While water is running, get under the sink with your flashlight and check every connection for leaks. Look at the supply line fittings, the faucet inlets, and the base of the faucet.
If you see drips, turn off the water, tighten the leaking connection by 1/8 turn, and test again.
Verify it worked
Run water on both hot and cold for 2 minutes. Check under the sink again. If everything is dry, you’re done with the plumbing.
If your faucet requires caulk around the base (check the manufacturer’s instructions), apply a thin bead of silicone caulk and smooth it with a wet finger. Let it cure for 24 hours before heavy use.
Troubleshooting
Problem: Water still flows after turning off shut-off valves
The valve isn’t working. Do not proceed. Turn off the main water supply and consider replacing the shut-off valves before continuing. This is a 15-minute job but requires shutting off water to the whole house. If you’re uncomfortable with it, call a plumber.
Problem: Old supply lines won’t budge
They may be corroded or over-tightened. Apply penetrating oil (like WD-40) and wait 10 minutes. If they still won’t turn, cut them with a hacksaw and replace them. New braided supply lines are $5–$10 per pair.
Problem: Mounting nut is stuck
Use the basin wrench with steady pressure. If it’s completely seized, spray with penetrating oil and wait. Do not force it with a pipe wrench—you risk cracking the sink.
Problem: Faucet spins or wobbles after installation
The mounting nut isn’t tight enough. Use the basin wrench to snug it down. If the faucet still spins, check that the gasket is seated properly.
Problem: Leaks at the base of the faucet
Either the gasket wasn’t seated correctly or caulk is needed. Remove the faucet, reseat the gasket, and reinstall. If the manufacturer requires caulk, apply it only after confirming there are no leaks at the connections.
When to call a professional
Call a plumber if:
- Shut-off valves are missing, stuck, leaking, or won’t turn
- Old supply lines are so corroded they break when you try to loosen them
- The sink deck is cracked around the faucet hole
- Water comes out of the supply line after turning off the shut-off valve (indicates a faulty valve)
- You experience leaks you can’t locate or fix after installation
The cost of a plumber visit ($150–$300 labor + faucet markup) is worth it if you encounter structural issues or if forcing a stuck valve risks flooding your kitchen and cabinets.
Product recommendations
Budget option: Single-handle pull-down (~$50–$80) Kohler Forte or Moen Essie. Simple to install, one supply line, fewer failure points. Best for renters or secondary sinks.
Mid-range: Two-handle bridge-style (~$120–$200) Delta Classic or Moen Banbury. Durable, easy to repair, widespread parts availability. Best for primary kitchen sinks and homeowners wanting longevity.
Premium: Touchless pull-down (~$200–$400) Kohler Sensate or Moen MotionSense. Modern look, hands-free operation. Note that sensor failures are outside DIY repair scope. Worth it if budget allows and you want the aesthetic.
Supply line note: Always choose braided stainless steel over PVC. The $2–$3 premium prevents future leaks.
FAQ
How long does it take to replace a kitchen faucet?
Most people finish in 1–2 hours. The job takes longer if you need to remove corroded supply lines or if the mounting nut is stuck. Budget 30 minutes for cleanup and testing.
Do I need a plumber to replace a kitchen faucet?
No, unless you encounter complications like missing or non-functional shut-off valves, corroded supply lines, or a cracked sink deck. The job requires basic tools and attention to detail, but it’s within hobbyist scope.
Can I reuse old supply lines with a new faucet?
Yes, if they’re not corroded and fit the new faucet’s inlets. But new braided stainless steel lines are $5–$10 per pair and prevent future leaks. I replace them every time.
What if my shut-off valves won’t turn?
Don’t force them. Corroded valves can break and flood your kitchen. If they’re stuck, call a plumber to replace them before continuing. It’s a small job that prevents a big mess.
Why is a basin wrench necessary?
The mounting nut is behind the faucet body in a tight space. A basin wrench has a pivoting jaw designed to reach it. Without one, you’ll spend an hour contorting or you’ll give up and call a plumber. It costs $8–$15 and you’ll use it on every faucet job forever.
The most common reason people call a plumber after attempting this job is a leak they can’t stop. The fix is almost always tightening the supply line connection by 1/8 turn—not wrenching it down. Take your time, test before you caulk, and you’ll save $200–$400 in labor while learning a skill that applies to bathroom sinks, laundry hookups, and every faucet in your house. For related under-sink work, see how to unclog kitchen sink and fix leaky faucet.