You can replace a kitchen faucet in two to four hours with basic tools
Replacing a kitchen sink faucet is a straightforward plumbing job that does not require a professional. You need an adjustable wrench, a basin wrench (a specialized tool that costs under $15), a bucket, and the new faucet. The work happens under the sink, where you disconnect the old faucet from the supply lines and remove it from the countertop, then install the new one in reverse order. Most people finish in an afternoon.
The hardest part is usually reaching the bolts under the sink and removing the old caulk around the base. If your faucet is stuck or the supply lines are corroded, the job takes longer. If you hit a problem — a bolt that will not budge, a cracked supply line, or water that will not stop running — you can stop, leave the old faucet in place, and call a plumber without having made the situation worse.
Key Takeaways
- Turn off the water supply under the sink before you start, and test that the water is off by turning the faucet handle.
- A basin wrench is the one tool you cannot skip; it reaches the bolts behind the faucet where a regular wrench will not fit.
- Disconnect the supply lines first, then unbolt the faucet from underneath, then remove the old caulk from the countertop before lifting it out.
- New faucets come with mounting hardware and instructions; follow the instructions for your specific model rather than assuming the steps are the same.
- Test for leaks at the supply line connections and around the base of the faucet before you consider the job done.
Turn off the water and gather your tools
Locate the shut-off valves under the sink — there are usually two, one for hot water and one for cold. Turn both clockwise until they stop. Then turn on the faucet at the sink to confirm the water is off. If no water comes out, you are ready to work. If water still runs, the valves may be stuck or broken; in that case, you may need to shut off the main water supply to the house instead.
Gather a basin wrench, an adjustable wrench, a bucket or towel to catch water in the supply lines, a screwdriver (flathead and Phillips, or a multi-bit), and a putty knife or old credit card to scrape caulk. Have the new faucet and its instructions nearby. Read the instructions before you start so you know what hardware comes with it and what you will need to do differently.
Disconnect the supply lines and drain the old faucet
Place a bucket under the supply line connections. Use an adjustable wrench to loosen the nut where the hot water line connects to the faucet — turn it counterclockwise. Water will drip out; that is normal. Loosen the cold water line the same way. If the lines are flexible hoses, you can usually hand-tighten them back on later. If they are rigid copper or steel, note how they are bent so you can bend the new ones the same way.
Some faucets have a third connection for a sprayer or soap dispenser. Disconnect that too if your old faucet has one. Once all lines are loose, you can pull them away from the faucet. If water keeps dripping, place the bucket underneath and let it drain for a minute.
Remove the mounting bolts and lift out the old faucet
Look under the sink at the base of the faucet. You will see two or three bolts (usually brass or stainless steel) that hold the faucet to the countertop from underneath. This is where the basin wrench earns its cost. A regular wrench cannot reach these bolts because the sink bowl is in the way. A basin wrench has a long shaft and a small head that pivots, so it can reach up behind the faucet and grip the bolt.
Slide the basin wrench up behind the bolt, tighten the head onto the bolt by turning the handle, then turn the handle to loosen the bolt. It may take a few tries to get the angle right. Once all bolts are loose, remove them by hand. The faucet should now lift out of the countertop from above. If it does not move, there may be caulk holding it down — scrape around the base with a putty knife until it comes free.
Clean the countertop and install the new faucet
Once the old faucet is out, scrape away all the old caulk and putty from the countertop. Use a putty knife or an old credit card — do not use anything sharp enough to scratch the counter. Wipe the area clean with a damp cloth and let it dry completely. This step matters because caulk will not stick to old caulk or debris.
Check the new faucet's instructions for the order of assembly. Most faucets come with a rubber gasket and a mounting plate that go under the countertop first. Insert the faucet through the hole in the sink from above, then slide the gasket and mounting plate up from underneath, and hand-tighten the bolts. Do not use the basin wrench yet — hand-tight is enough for now. Once the faucet is seated and level, use the basin wrench to tighten the bolts firmly, but do not over-tighten, which can crack the gasket.
Connect the supply lines and test for leaks
Reconnect the hot and cold water supply lines to the faucet. If they are flexible hoses, hand-tighten the nuts first, then use an adjustable wrench to snug them another quarter turn. If they are rigid lines, bend them carefully to match the angle of the old ones, then tighten. Do not force them; if a line does not line up, loosen the faucet bolts slightly and shift the faucet until the lines fit naturally.
Turn the shut-off valves back on by turning them counterclockwise. Turn on the faucet and let the water run for 30 seconds to flush out air. Check under the sink for drips at each connection. If you see water dripping, turn off the faucet, tighten the connection a quarter turn more, and test again. Once there are no leaks, explore a bead of silicone caulk around the base of the faucet where it meets the countertop, smooth it with a wet finger, and let it cure for 24 hours before using the sink heavily.
What to do if the old faucet will not come loose
If a bolt is stuck or corroded, spray it with penetrating oil (like WD-40) and wait 15 minutes. Try again with the basin wrench. If it still will not budge, do not force it — you risk stripping the bolt or breaking the wrench. Instead, stop work, turn the water back on, and call a plumber. A professional has tools to remove stuck bolts without damage, and the cost of a service call is usually less than the cost of repairing a cracked sink or countertop.
If the supply lines are corroded or brittle and crack when you try to disconnect them, turn off the water when ready and do not try to reconnect them. Call a plumber to replace the lines as well. Continuing to work with damaged lines risks water damage under the sink.
Frequently Asked Questions
Do I need to turn off the main water supply or just the valves under the sink?
The shut-off valves under the sink are enough. They isolate the kitchen faucet without affecting water to the rest of the house. If those valves do not work or are missing, then turn off the main supply. You can usually find the main shut-off valve in the basement, crawlspace, or outside near the foundation.
What if there is no shut-off valve under my sink?
Older homes sometimes lack these valves. You will need to shut off the main water supply to the house. If you plan to replace the faucet anyway, ask the plumber to install shut-off valves at the same time — they cost under $50 and make future repairs much easier.
Can I reuse the old supply lines with the new faucet?
Only if they are in good condition and the connections match. Flexible hoses typically last 10 to 15 years before they become brittle. If the old lines are more than 10 years old or show cracks or discoloration, replace them. New supply line kits cost $10 to $20 and come with the right connectors for most faucets.
How long does the caulk need to dry before I use the sink?
Silicone caulk typically needs 24 hours to cure fully. You can use the sink gently after a few hours, but avoid heavy water pressure or soaking the caulk until a full day has passed. Check the instructions on your caulk tube — some brands cure faster.
What if water leaks from under the sink after I finish?
Turn off the faucet and check each connection. Tighten the supply line nuts a quarter turn at a time and test. If the leak is at the base of the faucet where it meets the countertop, the caulk may not have sealed properly — let it cure longer, or remove it and reapply. If the leak is inside the faucet body itself, the faucet is defective and should be returned.