How to Replace a Kitchen Faucet (DIY)
Learning how to replace a kitchen faucet is one of the most rewarding DIY plumbing jobs: most homeowners finish in one to two hours, need only basic tools, and save $250-$600 in plumber labor. Modern faucets are designed for homeowner installation, with quick-connect fittings and mounting hardware that works from above the sink. This guide walks you through the whole job step by step, including the tricks for the two things that actually cause trouble — corroded mounting nuts and cramped under-sink space.
Tools and Parts You Will Need
Gather everything before you start so you are not crawling out from under the sink mid-job. You will need: an adjustable wrench, a basin wrench (the long-handled tool made for hard-to-reach faucet nuts — about $15 at any hardware store and worth every penny), channel-lock pliers, a flashlight or headlamp, an old towel and a small bucket, plumber's putty or the silicone sealant your faucet instructions specify, and Teflon tape. If your new faucet did not include supply lines, buy braided stainless steel supply lines in the right length — measure the distance from the shutoff valves to the faucet connections and add a few inches of slack.
Before buying, check your sink setup. Count the holes: a standard kitchen sink has one, three, or four holes. A single-hole faucet fits a one-hole sink; a faucet with a separate sprayer or soap dispenser needs extra holes. If your new faucet covers fewer holes than your sink has, buy matching hole covers. Also check your shutoff valves under the sink — if they are old multi-turn valves that drip or will not close fully, replace them now while the water is off, or you will be doing this job twice. For a deeper look at what is under there, see our under-sink plumbing guide.
Step 1: Shut Off Water and Prep
Start by turning off the hot and cold shutoff valves under the sink — turn them clockwise until they stop. Then open the old faucet to release pressure and confirm the water is actually off. If a valve drips or will not turn, do not force it until it breaks; shut off the house main instead and plan to replace that valve. Place a towel and bucket under the sink to catch the water that remains in the lines and the faucet body.
Next, clear everything out from under the sink and lay down a headlamp or flashlight where it shines up at the faucet connections. Take a phone photo of the existing connections — supply lines, sprayer hose, and mounting nuts — before you touch anything. That photo is your fallback if you get confused during reassembly. If your faucet has a side sprayer or a soap dispenser, note how their hoses route through the sink holes. Finally, read your new faucet's instructions once through before starting; brands differ on details like whether to use plumber's putty, whether the mounting plate goes above or below, and how the quick-connect sprayer hose locks in place.
Step 2: Remove the Old Faucet
Disconnect the supply lines from the shutoff valves first, using the adjustable wrench, and let them drain into the bucket. Then disconnect the sprayer hose if there is one — many use a quick-connect fitting you squeeze to release. Now the mounting nuts: these are up under the sink, threaded onto the faucet shanks, and they are the hardest part of the job. Use the basin wrench to reach them; turn counterclockwise and be patient. If a nut is corroded solid, spray it with penetrating oil, wait fifteen minutes, and try again.
Once the nuts are off, lift the old faucet out from above the sink. Scrape off old plumber's putty or sealant from the sink surface with a plastic scraper so the new faucet seats on a clean surface — leftover putty is a common cause of slow leaks around the base. Clean the sink holes and check the deck for rust or damage while you have access. If the sink deck is rusted through around a hole, that is a sink replacement problem, not a faucet problem, and it is worth knowing before you install a new faucet on a failing sink. If you are also replacing the sink itself, our kitchen sink installation cost guide explains what that job involves.
Step 3: Install the New Faucet
Follow your faucet's instructions for the base seal: some use a rubber gasket alone, some require a ring of plumber's putty under the base plate, and some specify silicone. Do not guess — the wrong sealant can void a warranty or leak. Feed the faucet's supply lines and sprayer hose down through the sink hole, set the faucet in place, and center it. From underneath, thread on the mounting hardware: usually a washer and nut, or a mounting bracket with screws that tighten from above on newer designs.
Tighten the mounting nuts snugly but not with all your strength. Over-tightening can crack a porcelain sink or warp the faucet base so it rocks. The faucet should not wobble when you push it side to side, but the base plate should not be digging into the sink either. If your faucet has a separate sprayer or soap dispenser, install those in their holes now, using the same seal-and-tighten approach. Route the sprayer hose so it hangs freely under the sink with a weight attached at the right spot — the weight is what retracts a pull-down sprayer, and if the hose snags on the disposal or a shutoff valve, the sprayer will not retract properly.
Step 4: Connect Supply Lines and Test
Connect the new supply lines to the shutoff valves: hot to hot (usually the left valve) and cold to cold. Hand-tighten first, then give each connection a quarter to half turn with the wrench. Do not over-tighten braided lines — the rubber washer inside does the sealing, and crushing it causes leaks. If your faucet uses quick-connect fittings, push them firmly until they click and tug gently to confirm they are locked. Wrap threaded connections with Teflon tape only where the instructions say to; many modern fittings seal with washers and tape actually interferes.
Now test slowly. Turn on the cold valve partway, check every connection with a dry hand and a flashlight, then turn it fully on and repeat for hot. Run the faucet for a minute, then check again — some leaks only appear under full pressure. Run the sprayer and check its hose connections too. If you see a drip at a supply connection, tighten it an eighth of a turn and recheck; if it persists, turn the water off, disconnect, and check the washer for damage or debris. A leak at the faucet base usually means the base seal needs redoing. Leave a dry paper towel under the connections overnight and check it in the morning — a slow drip you catch on day one is a five-minute fix, while one you discover a month later can ruin a cabinet floor.
Dealing With Stuck Nuts and Tight Spaces
Two problems turn an easy faucet swap into a frustrating afternoon, and both have solutions. First, stuck mounting nuts: years of moisture corrode them onto the shank. Penetrating oil and patience solve most cases; give the oil at least fifteen minutes to work, and tap the nut lightly to help it penetrate. If the nut still will not move, a basin wrench with a longer handle gives more leverage, and as a last resort a hacksaw blade or a nut splitter can cut the nut off — work carefully to avoid scoring the sink or the shank threads you might reuse.
Second, tight under-sink space: garbage disposals, water filters, and dishwasher hoses all compete for room. Remove the disposal temporarily if it blocks access — it unbolts from its mounting ring in minutes and saves you an hour of contortion. A headlamp beats a handheld flashlight because it keeps both hands free. And if your shutoff valves are buried behind the disposal, consider replacing them with quarter-turn ball valves while you are down there; they are more reliable and easier to operate in an emergency. Knowing the layout under your sink pays off here — our under-sink plumbing guide maps every part so you can find things by feel in the dark.
When to Call a Plumber Instead
DIY faucet replacement is a great project, but know when to stop. Call a plumber if the shutoff valves will not close and you cannot shut off the house main, if the sink deck is rusted or cracked, if supply lines are corroded into the valves, or if your new faucet requires moving supply lines or drilling new holes in a stone countertop. Also call a plumber if you discover active leaks, mold, or water damage under the sink — a faucet swap will not fix a rotting cabinet floor, and the underlying problem needs attention first.
Cost-wise, a plumber charges $250-$600 to replace a kitchen faucet in 2026, including labor and basic parts, so the DIY savings are real but not enormous. If you have already spent two hours fighting a stuck nut, there is no shame in calling in help — a plumber with the right tools finishes in under an hour. For more kitchen plumbing projects, browse our kitchen plumbing hub, and check our kitchen faucet installation cost guide if you want pro pricing before deciding. If you run into trouble mid-job, a local licensed plumber can usually get you sorted the same day.