What the trap does

The P-trap is the U-shaped bend below the sink. It always holds a little water, and that water seal keeps sewer gas out of the kitchen. Because it is the lowest point right under the basin, it is also where heavy food, grease clumps, coffee grounds and the occasional bottle cap tend to settle.

Most modern kitchen traps are plastic with large slip nuts you can loosen by hand or with pliers. Older homes may still have metal traps or threaded fittings that have corroded. Those are a reason to stop and call rather than force anything.

What you need

  • A bucket or shallow pan that fits under the trap
  • Old towels for the cabinet floor
  • Rubber gloves and eye protection
  • Slip-joint pliers, used gently
  • A bottle brush or old toothbrush
  • A flashlight

Removing and rinsing the trap

  1. Empty the cabinet

    Clear out cleaning supplies, lay towels down and place the bucket under the trap.

  2. Turn off the disposal

    Switch it off so no one runs it while the trap is open.

  3. Loosen the two slip nuts

    Turn them counterclockwise by hand first. Use pliers only if needed, and lightly.

  4. Drop the trap into the bucket

    Expect water and debris. Note how the washers sit so you can put them back the same way.

  5. Clean it out

    Rinse the trap in a utility sink or outside, not in the clogged sink. Brush out grease and food. Look into the trap arm with a flashlight.

  6. Reassemble and test

    Seat the washers, hand-tighten the nuts, then run water and check for drips. Snug slightly if it weeps.

When to stop

  • IfNuts will not turn or the metal is flakingThenStop. Forcing corroded fittings can break the trap arm inside the wall.
  • IfThe trap is clean but the sink still backs upThenThe clog is in the trap arm or branch line; it needs a cable.
  • IfIt leaks after reassemblyThenCheck the washer seating; replace worn washers or call.
  • IfA chemical opener was usedThenDo not open the trap; tell a plumber.

Common questions

Is it normal for water to sit in the trap?

Yes. That standing water is the seal that blocks sewer gas. What is not normal is food and grease filling the bend.

Can I replace a corroded metal trap myself?

Some homeowners do, but the risk is at the trap arm, which may be old metal threaded into the wall. If it breaks there, it becomes a plumbing repair inside the wall.

How tight should the slip nuts be?

Hand-tight plus a small turn is usually enough for plastic. Overtightening can crack the nut or distort the washer.

General information for Fullerton, not a quote or professional advice. In an emergency, call 911.