Symptoms
- Sink drains very slowly or not at all
- Clog seems to be right under the sink rather than further away
- Removing and clearing the trap noticeably restores flow
- Smell coming from the trap area
Likely causes
- CommonHair, soap, or food debris settled in the curve of the trapThe trap's shape naturally catches debris that doesn't fully wash through.
- CommonGrease hardened inside the trapEspecially common in kitchen sink traps.
- PossibleForeign object lodged in the trapSmall items dropped down the drain often stop here.
- Less commonMineral scale narrowing the trap over many yearsMore relevant in very old metal traps.
What to do
- Place a bucket under the trap to catch water and debris.
- Loosen the slip nuts on both ends of the trap by hand or with pliers, keeping the bucket positioned underneath.
- Remove the trap fully and empty its contents into the bucket or a trash bag.
- Use a bottle brush or a straightened wire hanger to scrub out any remaining residue inside the trap.
- Inspect the washers on each end for wear and replace if flattened or cracked.
- Reinstall the trap, hand-tightening the nuts and giving them a partial turn with pliers.
- Run water and check both for normal drainage and for any leaks at the reassembled joints.
Tools and parts
- Adjustable pliers
- Bucket
- Bottle brush
P-trap slip nut washersSearch: “sink trap slip nut washer kit”
When to call a pro
Call a plumber if the trap is clear but the sink still doesn't drain, since the clog is further down the line.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.