Swapping a worn-out fixture for a new faucet is one of the quickest ways to freshen up a kitchen, and it costs far less than you might think. It looks like serious plumbing, but it is a manageable afternoon project for most homeowners.
You do not need a license or years of experience. With a basin wrench, a few common tools, and some patience under the sink, you can handle the whole job yourself and save on labor.
This guide walks you through removing the old hardware and installing your new kitchen faucet step by step, plus how to measure for the right fit and seal it so it will not leak.
Key Takeaways
- Shut off the water first: Close the hot and cold supply valves under the sink and open the faucet to release pressure before you loosen any nut.
- Clear and light the cabinet: Empty the under-sink cabinet, set up a headlamp or work light, and keep a bucket and towels ready for trapped water.
- Use a basin wrench: A basin wrench reaches the mounting nuts behind the sink basin that no other tool can, which is the key to both removal and install.
- Fit new lines, then flush: Replace the old supply lines with braided stainless steel, then run the faucet with the aerator off to clear out debris.
Before You Start
Replacing a kitchen faucet is straightforward, but you need to prepare. You want to avoid realizing you are missing a specific washer or tool halfway through the job with the water turned off.
Plan Ahead
Step 1: Gather Your Tools
Make sure you have these items within reach before you crawl under the sink:
- Replacement faucet
- Basin wrench (essential for tight spaces)
- Adjustable wrench
- Flashlight or headlamp
- New supply lines (if not included with the faucet)
- Old towels or rags
- Putty knife
- Small bucket or shallow bowl
- Safety glasses
Step 2: Check the Manufacturer Instructions
Every brand is slightly different. While the general mechanics are the same, the specific washers, locking nuts, and order of operations vary between Moen, Delta, and Kohler.
Always defer to the manual included in your box. If you tossed it, look up the model number online to find a PDF version.
Step 3: Clear the Cabinet
You need room to work. Remove all cleaning supplies, sponges, and trash cans from the cabinet under the sink.
This creates space for you to lay on your back and reach the plumbing. It is also a good excuse to declutter the area; just keep an eye out for spiders.
How to Replace a Kitchen Faucet
Once your tools are ready and the cabinet is empty, you can start the heavy lifting.
Follow these steps to swap out your fixture:
Step 1: Turn Off Supply Valves
You must cut the water flow before detaching anything. Locate the hot and cold valves under the sink and turn them clockwise until they stop.
Once closed, open the faucet handles above the sink to drain remaining pressure. If water continues to drip after a minute, your valves might be faulty. In that case, you may need to shut off the main water to the house or call a plumber to replace the valves.
If the flow stops, disconnect the supply lines from the valves. Place a bowl underneath to catch the small amount of water trapped in the hoses. Before you pull the lines free, mark which is hot and which is cold with a piece of tape, so you can match them to the correct valves later. Use your basin wrench or adjustable wrench to turn the nuts counter-clockwise.
Step 2: Light the Area
Visibility under a sink is notoriously poor. Set up a work light or wear a headlamp. Seeing exactly which nut you are turning prevents you from stripping threads or damaging the plumbing.
Step 3: Remove the Old Faucet
This is often the hardest part due to corrosion. Use a basin wrench to reach up behind the sink basin and locate the mounting nuts holding the faucet in place.
Turn the nuts counter-clockwise. If they are plastic, try turning them by hand first. If metal nuts are rusted shut, apply a penetrating oil and let it sit for a few minutes before trying again.
Once the nuts are off, go above the sink. If the faucet feels stuck, the gasket or old putty may have bonded to the sink deck. Gently slide a putty knife under the rim to break the seal. Lift the faucet out and pull the hoses through the hole.
Step 4: Clean the Mounting Surface
Your old faucet likely left behind a ring of grime, hard water deposits, or dried putty. Scrape this off with your putty knife and wipe the area clean with a rag and household cleaner.
You need a smooth, clean surface to ensure the new faucet seals tightly against the sink.
Step 5: Install the New Faucet
Feed the new supply lines and shank through the hole(s) in the sink. If your new faucet includes a plastic gasket or trim ring, ensure it is positioned correctly at the base of the faucet.
From underneath, slide the washer and mounting nut onto the shank. Tighten the nut by hand until it is snug against the underside of the sink, then give it a final tighten with your basin wrench.
Note: Do not overtighten. This can crack the nut or damage the faucet body.
Using A Deck Plate
Step 6: Connect the Supply Lines
Connect the corresponding supply lines to the shut-off valves. Usually the hot water is on the left and cold is on the right, matching the tape you added earlier.
Fit new braided stainless steel supply lines rather than reconnecting the old hoses. Hand-tighten the nuts onto the valves, then give them about a quarter turn, roughly 90 degrees, with an adjustable wrench (1).
Note: Stop there. Overtightening a supply nut strips the threads or cracks the fitting, and that is one of the most common reasons a fresh install leaks.
Step 7: Install the Weight (Pull-Down Models)
If your faucet has a pull-down sprayer, you need to install the counterweight on the sprayer hose. This weight pulls the hose back into the spout after you use it.
Check the instructions for the exact placement. It usually clips onto the hose loop to ensure it moves freely without catching on drain pipes.
Step 8: Flush the System
New faucets can contain manufacturing debris that clogs the aerator.
- Remove the aerator: Unscrew the tip of the spout (the aerator) and set it aside.
- Turn on the water: Slowly open the hot and cold supply valves under the sink.
- Run the tap: Turn the faucet handle on full blast. Let the water run for 1 to 2 minutes to flush out any sediment.
- Reassemble: Turn the faucet off, screw the aerator back on, and you are done.
Step 9: Check for Leaks
With the water running, use a flashlight to inspect all connections under the sink. Run a dry paper towel over the supply lines and valves. If the paper towel picks up any moisture, you have a small leak. Tighten the connection slightly and check again.
Stiff Valves
How to Measure for a New Faucet
Buying the wrong size faucet is a common mistake. You need to ensure the new unit fits your sink configuration and clears any cabinets.
1. Count the Holes
Look at your sink deck. How many holes are there?
- 1 Hole: Ideal for single-handle faucets.
- 2 Holes: Usually one for the faucet and one for an accessory like a soap dispenser or side sprayer.
- 3 Holes: Standard for double-handle faucets or a single-handle faucet with a deck plate.
- 4 Holes: Accommodates a two-handle faucet plus a side sprayer.
If you buy a single-hole faucet but have three holes in your sink, you must use the included deck plate to cover the gaps. Standard faucet holes measure about 1-3/8 inches across, though some faucets need a slightly larger 1-1/2 inch opening, so check the specs before you buy (2).
2. Check Clearances
Measure the distance from the faucet hole to the wall or backsplash. Ensure the handle of your new faucet has enough room to rotate fully backward without hitting the wall.
Also, measure the height. If you have a shelf or cabinet directly above the sink, a high-arc “gooseneck” faucet might not fit.
3. Spout Reach
Measure the distance from the mounting hole to the center of the sink bowl. You want the water stream to hit near the drain. If the spout reach is too short, you will struggle to wash large pots; if it is too long, it might splash water onto your shirt.
What Is Plumber’s Putty?
Plumber’s putty is a clay-like compound used to create a watertight seal between the faucet and the sink deck. It stays pliable for a long time, allowing for a tight seal that does not crack (3).
Do You Need It?
Not always. Most modern faucets come with a rubber or plastic gasket that sits at the base. If your faucet has this gasket, you do not need plumber’s putty. In fact, using putty with a gasket can prevent it from sealing correctly.
Warning: Do not use plumber’s putty on porous materials like granite, marble, or composite stone. The mineral oils in the putty can stain the stone permanently. In these cases, use a 100% silicone sealant made for stone.
