How to Install a Kitchen Faucet
Modern kitchen faucet installation is 60 minutes if you have access. Older sinks with corroded mounting nuts can extend that to 2 hours.
TL;DR
Standard kitchen faucet installation: 60 minutes. The hard part is loosening corroded mounting nuts under the sink in older LA homes. Use penetrating oil and a basin wrench. Don’t over-tighten supply lines.
What’s in this guide
- Pre-install checklist
- Removing the old faucet
- Installing the new faucet
- Connecting supply lines
- Testing
Kitchen faucet installation is one of the more common DIY plumbing projects. The procedure is straightforward; the only challenge is access (you’ll spend most of your time on your back under the sink) and corroded mounting hardware on older installations.
Tools & Materials You’ll Need
Tools
- Basin wrench
- Adjustable wrench
- Phillips and flathead screwdrivers
- Penetrating oil (PB Blaster)
- Bucket
- Towels
- Flashlight or headlamp
- Knee pad
Materials
- New kitchen faucet
- New braided stainless supply lines (if not included with faucet, $12 each)
- Plumber’s putty or silicone (most modern faucets include a base gasket; check)
- Plumber’s tape (PTFE)
Step-by-Step Instructions
Shut Off Water and Disconnect
Close the hot and cold supply valves under the sink. Open the faucet to relieve pressure. Disconnect the existing supply lines at the faucet (top connection) — water in the lines will drip into your bucket.
Remove Old Faucet
Use a basin wrench to loosen the mounting nuts holding the faucet to the sink (these are above the threaded shanks of the faucet, accessed from underneath). On older installations, these are often corroded — apply penetrating oil and wait 15 minutes. Once loose, remove nuts. The faucet lifts up and out from above.
Clean the Sink Surface
With the old faucet out, scrape off old plumber’s putty or sealant from the sink top. Clean thoroughly with rubbing alcohol. The new faucet’s base gasket needs to seal against clean metal.
Position the New Faucet
Most modern kitchen faucets come with a base gasket pre-installed. Position the faucet centered on the sink, with the supply tubes going down through the mounting hole(s). For pull-down sprayer faucets, also feed the sprayer hose through.
Tighten Mounting Nuts From Below
Hand-tighten the mounting nuts up against the sink underside. Then snug with the basin wrench — JUST until firm, NOT crank-tight. Over-tightening can crack the faucet base or the sink.
Connect Supply Lines
Connect the braided stainless supply hoses to the faucet shanks (above) and to the shutoff valves (below). Apply PTFE tape on threaded fittings. Hand-tight + 1/4 turn with a wrench. Hot to hot, cold to cold.
Turn On Water and Test
Slowly open both supply valves. Watch ALL connections — under the sink and at the faucet base — for any water. Run hot, cold, and mixed for 60 seconds each. Test the sprayer if applicable. Check under the sink with paper towels for slow drips after 30 minutes.
Across LA installs, the most common mistake we see homeowners make is reusing old supply lines. They look fine outside but the rubber inner liner has been pressurized for years and is at the end of its service life. Cracked supply lines under sinks are a top-5 emergency call we receive — usually catastrophic flooding overnight. New stainless braided supply lines: $12 each. Replace them every time.
Don’t skip the supply line replacement
Old supply lines fail catastrophically. New ones cost $24 for the pair. Always replace.
Real Scenarios from Our LA Service Calls
New faucet, old supply lines
Homeowner installed a beautiful new Brizo kitchen faucet in their 1932 estate. Saved the original 12-year-old supply lines. 14 days later, the cold-water supply line burst at 2 AM, flooding the kitchen and dripping through to the basement. Service call to repair: $385 plus $1,800 in damage. New supply lines would have been $24.
When to Call a Plumber Instead
DIY isn’t always the right call. Bring in a licensed plumber if any of these apply:
- Sink mounting nuts are completely seized
- Sink top damaged during removal
- You’re installing a touchless or smart faucet (electrical hookups required)
- Multiple-handle faucet replacing single-handle (additional drilling)
Frequently Asked Questions
Can I install a 1-handle faucet in a 3-hole sink?
Yes — most single-handle faucets include a deck plate that covers the unused holes. Check that the new faucet includes one for your sink configuration.
Do I need plumber’s putty?
Modern faucets usually have a base gasket — no putty needed. Older or premium faucets sometimes specify silicone or putty under the base. Check instructions.
Why is my new faucet noisy?
Usually trapped air in the lines. Run hot and cold separately at full flow for 1 minute each. Should clear. If persistent, check that you didn’t kink a supply line during install.
How long should a kitchen faucet last?
Quality brand (Moen, Delta, Kohler): 12–18 years. Premium (Brizo, Grohe, Hansgrohe): 15–25 years. Cheap: 3–5 years. Quality is worth the upfront cost.
Can I install a touchless faucet myself?
Yes, if you have access to power. Touchless faucets need 6V battery (replace every 2–4 years) or hardwired transformer. Battery is simpler.
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