Miles SinclairBy Miles Sinclair

Updated November 2026

Kitchen sink faucet replacement is a manageable weekend job for most homeowners with basic tools and a little patience. In this guide, you will learn how to prepare the sink, remove the old faucet, install the new one and test it for leaks. The process is the same for most single-hole and three-hole models, with a few differences in mounting hardware.

Before You Start: Choose the Right Faucet and Check Your Sink

Start by measuring your sink. Count the mounting holes on the sink deck and note their spacing. A single-hole faucet fits one opening, while a three-hole faucet needs a separate spout hole plus handle holes. Check the faucet’s specifications for its mounting style and maximum deck thickness, then compare those figures to your sink.

Shopping for one? See our guide: 5 Best Faucets for Kitchen Sink Options Compared for Every Need (2026).

Also check the water supply lines. Most replacement faucets use flexible supply lines with 3/8-inch compression fittings at the shutoff valves. If your existing lines are old, brittle or corroded, replace them at the same time.

Shut Off the Water and Remove the Old Faucet

Close the under-sink shutoff valves by turning them clockwise. Then open the faucet to drain remaining water. Place a towel and a bucket under the sink to catch drips.

  1. Disconnect the supply lines from the shutoff valves using an adjustable wrench.
  2. Remove the mounting nuts or clips under the sink. A basin wrench reaches these in tight spaces.
  3. Disconnect any spray hose, weight or quick-connect fitting under the deck.
  4. Lift the old faucet out and scrape away old plumber’s putty or gasket material from the sink surface.

Install the New Faucet Step by Step

Clean the sink surface so it is dry and free of residue. Apply plumber’s putty or use the gasket that came with the faucet, depending on the manufacturer’s instructions. Feed the supply lines and any spray hose through the mounting hole.

  1. Set the faucet on the deck and align it with the holes.
  2. From below, slide the washers and mounting nuts onto the threaded shanks and tighten them evenly by hand, then finish with a wrench. Avoid overtightening, which can crack the sink or distort the base.
  3. Connect the supply lines to the shutoff valves. Hand-tighten first, then give each fitting a quarter turn with a wrench.
  4. Reattach the spray hose and weight, routing the hose so it hangs freely without kinks.

Test for Leaks

Open the shutoff valves slowly, one at a time. Run the faucet on hot and cold and check every connection under the sink for drips. Let the water run for about a minute, then tighten any fitting that weeps. Wipe the connections dry with a paper towel so small leaks are easy to spot.

Common Mistakes to Avoid

  • Skipping the shutoff valve check. If a valve does not close fully, shut off the main water supply before starting.
  • Overtightening plastic nuts or compression fittings, which can crack threads.
  • Forgetting to flush the new supply lines before connecting them, so debris does not clog the aerator.
  • Installing a faucet with a deck thickness outside its stated range, which causes wobble or loose mounting.
  • Reusing old, hardened gaskets or putty, which often leads to leaks at the base.
  • Basin wrench: Reaches mounting nuts in the cramped space behind the sink, where a standard wrench cannot fit. View on Amazon
  • Plumber’s putty: Seals the faucet base to the sink deck when the manufacturer calls for putty instead of a gasket. View on Amazon
  • Flexible braided supply lines: Give you a clean, leak-resistant connection to the shutoff valves when your old lines are worn. View on Amazon

For more on matching parts to your model, see Parts of a Kitchen Faucet: 6 Best Replacement Picks Compared (2026) and Moen Kitchen Faucet Replacement Parts: Find and Install the Right One. If you plan to swap only the spray hardware, Kitchen Sink Hand Sprayer Replacement: A Step-by-Step Guide (2026) covers that job.

FAQ

Can I replace a kitchen faucet without a plumber?

Yes, most homeowners can handle a standard single-hole or three-hole replacement with basic hand tools. If your shutoff valves are seized or your supply lines run into walls, a licensed plumber is the safer choice.

How long does kitchen sink faucet replacement take?

Most people finish in one to two hours, not counting time spent finding parts. Allow extra time if the old faucet is corroded and difficult to unscrew.

Do I need to replace the sink when I change the faucet?

No, the sink stays in place in most cases. You only need to replace the sink if the mounting holes do not match the new faucet and you cannot use a deck plate.

Conclusion

Kitchen sink faucet replacement comes down to three things: shutting off the water, removing the old unit cleanly and mounting the new faucet with careful, even tightening. Test every connection before you call the job finished. Following these steps will give you a leak-free faucet that works as expected.

Ready to choose one?

Miles Sinclair

About Miles Sinclair

Miles Sinclair is part of our editorial team and reviews and edits our kitchen faucets & sinks guides, checking product details against manufacturer specifications and owner feedback.