With the water shut off and residual pressure released, place your bucket under the supply lines. Using an adjustable wrench, turn the supply line nuts counterclockwise to disconnect them from the shutoff valves. Hot and cold lines will drip residual water — let them drain into the bucket.

Note which line is hot (left) and which is cold (right) before removing — or take a quick photo. Standard North American plumbing is hot on the left, cold on the right, but older kitchens can be non-standard.

Reach up behind the faucet using your basin wrench. Feel for the coupling nuts where the supply tubes connect to the underside of the faucet tailpieces — typically 10–14 inches above the cabinet floor. Engage the basin wrench jaw on the nut and turn counterclockwise to loosen. The long handle gives you the leverage you need in the tight space.

If the faucet came with pre-attached supply lines (common on modern faucets), the supply lines and faucet come out as one assembly — skip this step and go directly to removing the mounting nuts.

With the supply lines disconnected, locate the mounting nut(s) that hold the faucet body to the sink or countertop. On single-hole faucets there's typically one large plastic or metal nut directly under the faucet body. On 3-hole widespread faucets, each handle and spout has its own mounting nut.

Use the basin wrench to turn each mounting nut counterclockwise until it releases. Once all mounting hardware is removed, lift the old faucet straight up and out from the top of the sink.

If there's a separate side sprayer, disconnect its hose from the spray nipple under the old faucet (usually a threaded plastic fitting — turn counterclockwise by hand or with pliers), then pull the sprayer and hose assembly up through the sprayer hole.

After the old faucet is out, use a scouring pad to clean the sink surface around the faucet holes. Remove all old putty, silicone residue, and mineral scale. The new faucet's gasket or deck plate must seat against a clean, flat surface — any remaining putty ridge will prevent a proper seal and cause the new faucet to wobble or leak at the base.

If the old sprayer-hose escutcheon cap (the chrome ring around the sprayer hole) is still in good shape, you can leave it in place. If it's corroded, stained, or doesn't match the new faucet's finish, replace it with the one included with your new faucet.

Deck plate (for 3-hole sinks with single-hole faucets): If your new faucet includes a deck plate (escutcheon plate), attach it to the faucet body at this stage per the manufacturer's instructions — it typically snaps on or is secured with a set screw before the whole assembly goes into the sink.

Gasket vs. putty: Most modern faucets include a rubber or foam gasket that seals the faucet base to the sink surface — no additional putty required. If your faucet doesn't include a gasket, roll a rope of plumber's putty and press it around the underside perimeter of the faucet base.

On stone countertops (granite, engineered stone, marble): Do not use plumber's putty — it can stain certain stone finishes. Use the included gasket or apply a thin bead of silicone sealant instead.

If your new faucet does not have pre-attached supply lines, connect the new flexible braided supply lines to the faucet tailpieces now — before the faucet goes into the sink. Hand-tighten, then a quarter turn with pliers. This is dramatically easier on the countertop than reaching up from inside the cabinet.

Confirm supply line length: the lines need to reach comfortably from the faucet tailpieces down to the shutoff valves without kinking. Measure the distance before purchasing — standard 12" or 16" lines fit most installations, but deep base cabinets may need longer.

With the gasket or putty in place, carefully lower the faucet assembly into the sink hole from above. Guide the supply line tailpieces (and the pull-down hose, if applicable) down through the center hole first, threading them through before the faucet base contacts the sink surface.

On 3-hole widespread faucets, each piece (left handle, spout, right handle) drops into its own hole individually, then connects via flexible copper or plastic supply tubes underneath. Follow the manufacturer's diagram carefully for assembly sequence — widespread faucets vary significantly by brand.

Once the faucet is seated, confirm it is aligned straight — the spout should point directly toward the center of the sink and the handles should be level. Make this correction now, before tightening anything.

Crawl under the sink. Slide the provided washer (if included) onto the faucet tailpiece from below, then thread on the mounting nut — either a plastic nut, metal nut, or a combined plastic nut-washer unit depending on the faucet design.

Tighten by hand first until snug, checking from above that the faucet hasn't rotated out of alignment. Then use the basin wrench to tighten firmly — the jaw pivots to grip the nut as you push on the handle. Turn clockwise to tighten.

Do not overtighten — especially with plastic mounting nuts, which can crack. The goal is firm, with the faucet immovable when you push on the spout. If the faucet rotates or wobbles after tightening, the nut isn't engaged correctly — remove and try again.

Thread the male end of each supply line onto the corresponding shutoff valve — hot to the left valve, cold to the right. Most modern supply lines have a 3/8" compression fitting that seats with its internal rubber washer — no Teflon tape is needed for compression fittings.

Hand-tighten until snug, then turn a quarter to half turn more with an adjustable wrench. Do not overtighten — the rubber washer creates the seal, not the force of clamping. Overtightening crushes the washer and causes leaks.

If your supply lines have threaded male pipe ends (older shutoff valves), wrap the threads with 2–3 clockwise wraps of Teflon tape before connecting.

Separate side sprayer (4-hole faucets): Feed the sprayer hose down through the sprayer hole in the sink and connect it to the spray nipple on the underside of the faucet body — typically a quick-connect or threaded plastic fitting. Hand-tighten and confirm the hose has enough slack to extend from the sink without pulling on the faucet.

Pull-down / pull-out faucets: The spray hose is built into the faucet and feeds down through the center hole. Under the sink, connect the hose to the faucet body's outlet fitting (usually a quick-connect coupling or threaded connection per the manufacturer's instructions). Route the hose so it hangs freely without kinking when pulled out.

Install the hose weight: Pull-down faucets include a counterweight that clips or clamps onto the spray hose approximately 8–12 inches below the faucet body. This weight pulls the spray head back into the spout automatically when released. Without it, the head droops and won't retract. Clip the weight at the position indicated in the manufacturer's instructions — usually near the first hose curve.

Remove the aerator from the faucet spout before turning on the water. Installation debris — pipe scale, metal shavings, thread tape shreds — will flush through the new lines when water runs for the first time. Let this debris flush through freely rather than clogging in the aerator screen. Reinstall the aerator after flushing for 30–60 seconds.

Slowly open the hot shutoff valve, then the cold. Let water run for a full minute. Meanwhile, visually inspect — and run your dry fingertip across — every connection point:

• →Both supply line connections at the shutoff valves
• →Both supply line connections at the faucet tailpieces
• →Around the base of the faucet where it contacts the sink deck
• →The spray hose connection and nipple fitting
• →The sprayer hole escutcheon cap area

Tighten any connection that shows moisture — a quarter turn at a time. Reinstall the aerator and test hot/cold water, spray function, and handle movement. Leave a dry paper towel under all connections overnight — if it's dry the next morning, the installation is complete.