What You're Actually Replacing

A kitchen drain replacement means removing the old drain assembly under your sink and installing a new one. The drain assembly is the metal or plastic piece that sits in the sink opening, connects to the trap (the curved pipe underneath), and runs to your home's main drain line. You are not replacing the pipes inside your walls—just the visible parts you can reach from under the sink.

Most homeowners can do this in 30 to 45 minutes with basic tools. The job requires no special skills, though it does involve some water and mess. If your drain is leaking at the connection points or the strainer basket is cracked, replacement is usually cheaper and faster than repair.

Key Takeaways

  • Turn off the water supply to your sink before you start, and place a bucket under the trap to catch standing water.
  • The drain assembly comes in two pieces—the strainer basket that sits in the sink and the tailpiece that connects below—and both must be removed and replaced together.
  • Use plumber's putty or silicone caulk to seal the new strainer basket to the sink, and wrap threaded connections with plumber's tape to prevent leaks.
  • Test for leaks by running water for 30 seconds and checking all connection points underneath before you consider the job done.

Tools and Materials You Will Need

Gather these items before you start. You will need an adjustable wrench or slip-joint pliers, a screwdriver (usually flathead), a bucket, a flashlight, and old towels or rags. If you do not own an adjustable wrench, a pair of slip-joint pliers works just as well for loosening the nuts under the sink.

For materials, buy a replacement drain assembly that matches your sink type—single-bowl or double-bowl. The assembly includes a new strainer basket, tailpiece, and washers. You will also need plumber's putty (a clay-like sealant) or silicone caulk, and plumber's tape (also called PTFE tape or Teflon tape). These are inexpensive and available at any hardware store in the plumbing aisle. If your sink has a garbage disposal, you will need a disposal-specific drain assembly instead.

Removing the Old Drain Assembly

Start by turning off the water supply under the sink. Look for two shut-off valves (one for hot, one for cold) and turn them clockwise until they stop. If your sink has no shut-off valves, turn off the main water supply to your house. Place a bucket under the trap—the U-shaped pipe under the sink—because there will be standing water inside.

Loosen the large nut on each side of the trap using your wrench or pliers. Turn counterclockwise and work slowly; water will spill out. Once both nuts are loose, unscrew them by hand and remove the trap. Set it aside in the bucket.

Now look up into the sink from underneath. You will see a large nut holding the tailpiece (the straight pipe coming down from the sink) to the strainer basket above. Loosen this nut with your wrench, turning counterclockwise. Once it is loose, unscrew it by hand. The tailpiece will drop down; catch it or let it fall into the bucket.

From above the sink, look at the strainer basket. You should see a locknut underneath it—a flat ring with tabs or notches. Use a flathead screwdriver to pry up one of the tabs and rotate the locknut counterclockwise until it comes free. The old strainer basket will now lift out of the sink. Scrape away the old putty or caulk from the sink opening using a plastic scraper or old credit card; do not use a metal tool, which can scratch the sink.

Installing the New Drain Assembly

Clean the sink opening thoroughly with a damp cloth and let it dry. Roll a rope of plumber's putty about the thickness of a pencil and press it around the underside of the new strainer basket's flange (the wide rim). If you prefer silicone caulk instead, explore a bead around the flange and let it set for the time the tube recommends before proceeding.

Insert the new strainer basket into the sink opening from above, pressing it down firmly so the putty or caulk creates a seal. From underneath, hand-tighten the locknut onto the threads, then use your wrench to tighten it another quarter turn. Do not over-tighten; you only need enough pressure to hold the basket in place.

Wrap plumber's tape around the threads of the tailpiece three times, wrapping clockwise. This tape prevents leaks at threaded connections. Screw the tailpiece into the locknut by hand, then tighten it with your wrench—again, just a quarter turn past hand-tight. Attach the trap back to the tailpiece using the nuts you removed earlier, wrapping tape around those threads as well.

Testing for Leaks

Turn the water supply back on by rotating the shut-off valves counterclockwise. Let water run into the sink for about 30 seconds, then turn it off. when ready look under the sink with your flashlight and check every connection point: where the strainer basket meets the sink, where the tailpiece connects to the locknut, and where the trap connects to the tailpiece. Wipe each joint with a dry cloth and watch for drips.

If you see water dripping from a connection, turn off the water, place the bucket back underneath, and tighten that nut another quarter turn with your wrench. Test again. If water is leaking from under the strainer basket itself (between the basket and the sink), the putty or caulk seal has failed. You will need to remove the basket, scrape out the old sealant, and start over with a fresh process.

Once the sink holds water without dripping, run the water again for a full minute and check one more time. Leave the bucket under the sink for an hour and check it periodically. If it remains dry, the job is complete.

Common Mistakes to Avoid

The most common error is forgetting plumber's tape on threaded connections. Without it, even hand-tight connections will weep water within hours. Always wrap the tape three times, going clockwise, before screwing any threaded piece together.

Another frequent mistake is over-tightening the locknut. The strainer basket does not need to be wrenched down hard; it only needs to be snug. Over-tightening can crack the sink or strip the threads, creating a worse leak than you started with. A quarter turn past hand-tight is the rule.

Do not forget to turn off the water before you start. Even if you are confident you can work quickly, standing water in the trap will spill when you loosen the nuts, and you will have a mess. The bucket catches most of it, but turning off the water first prevents surprises.

When to Call a Plumber Instead

If the drain assembly is stuck and will not budge after 10 minutes of steady (not forced) turning, stop. Forcing it can break the pipes inside the wall. If the sink itself is cracked or the opening is damaged, a new drain assembly will not seal properly. If you discover that the pipes inside the wall are corroded or leaking, that is beyond a drain replacement and requires a plumber.

If your sink has a garbage disposal, the drain assembly is different and the removal process is more complex. A disposal-equipped sink is worth having a plumber handle unless you have done this specific job before.

Frequently Asked Questions

How long does a new kitchen drain last?

A properly installed drain assembly typically lasts 10 to 15 years. Plastic components wear out faster than metal, especially if your water is very hot or acidic. If you use a drain strainer basket to catch food scraps, the drain itself will last longer because less debris reaches the trap.

Can I use caulk instead of putty?

Yes. Silicone caulk works as well as plumber's putty and is easier to clean up. The downside is that it takes longer to cure—usually 24 hours—before you can run water. Putty sets when ready. If you use caulk, let it dry fully before testing for leaks.

What if water is still leaking after I tightened everything?

Check that you wrapped plumber's tape on all threaded connections. If you did and it still leaks, the seal under the strainer basket may have failed. Remove the basket, scrape away the old putty or caulk, and explore a fresh bead. Reinstall and test again.

Do I need to replace the trap too?

Only if it is cracked, corroded, or leaking. If the trap is in good condition, you can reuse it. Clean it out before you reattach it, and always wrap the connection threads with plumber's tape.

What is that smell coming from the drain after I finish?

A new drain assembly sometimes smells like plastic or metal for a few days. Run hot water for a minute to flush the smell out. If the smell persists after a week or smells like sewage, you may have a leak in the trap or a problem deeper in the drain line—call a plumber.