To fix a sink that won’t drain, clear the stopper, plunge, clean the P-trap, and snake the line in that order.
Slow water, gurgles, and standing puddles point to a clog near the top of the line. You can clear most kitchen and bathroom sinks with a short list of tools and a steady method. This guide walks you through the fixes from fastest to deepest, plus safety notes and prevention tips that keep the drain moving.
Fixing a sink that won’t drain: quick steps
Start with low-risk moves. Then step up only as needed. The aim is to loosen hair, soap scum, food bits, and grease without harming pipes or finishes.
| Symptom | Likely cause | First fix |
|---|---|---|
| Water stands still | Full blockage in trap or branch line | Plunge, then check P-trap |
| Drains slowly | Partial clog near stopper or tailpiece | Clear stopper; flush with hot water |
| Gurgling sounds | Air trapped by clog | Snake the line 10–15 feet |
| Bad odor | Rotting debris in trap | Remove and clean P-trap |
| Backs up into other sink | Shared branch is blocked | Snake from cleanout or remove trap |
| Leak under sink | Loose slip nuts or cracked trap | Re-seat washers; replace damaged parts |
Prepare the area and gear
Clear the cabinet. Put a bucket and towels under the trap. Slip on gloves and eye protection. Keep pets and kids out of the workspace. If a chemical drain opener was used, skip vinegar, bleach, or other cleaners until the line is fully flushed with plenty of water. Mixing chemicals can create dangerous fumes.
Step 1: free the stopper and tailpiece
Bathroom sinks often clog at the stopper where hair and toothpaste form a mat. Lift the stopper. If it won’t lift, reach behind the basin, loosen the small nut on the pivot rod, and slide the rod out to free the stopper. Clean it with a brush and hot water. For kitchen sinks with strainers, lift out the basket and scrub away fibrous food and coffee grounds. Flush the opening with a kettle of hot water.
Next, remove visible buildup at the top of the drain. A plastic zip-strip or a looped wire pulls hair mats without scratching chrome. Run hot water and see if flow returns. If not, move on.
Step 2: plunge the sink the right way
Fill the basin with a few inches of warm water. Seal the overflow hole with tape or a wet rag. For a double-bowl kitchen sink, plug the other bowl. Set a cup plunger flat over the drain and press down firmly to seat the rim. Pump in quick strokes for 20–30 seconds, then snap the plunger up to break suction. Repeat several rounds. Good plunging often clears a soft clog without taking anything apart.
Step 3: clean the P-trap
Place the bucket under the trap. Loosen the two slip nuts by hand or with tongue-and-groove pliers. Support the trap so you don’t stress the tailpiece. Tip the trap into the bucket. Scoop out sludge with a bottle brush and rinse outside if you can. Check the washers; replace if they look flattened or brittle. Reassemble by hand until snug, then a quarter turn with pliers. Run water and look for drips.
Step 4: snake the line
If the trap was clean or flow is still slow, feed a 1/4-inch hand auger through the wall pipe or the cleanout under the sink. Crank while pushing to bite into the clog. When you feel resistance, lock the set screw and rotate to break the plug. Pull back and wipe the cable, then feed again. Aim for 10–15 feet to reach the branch line. Flush with hot water for a minute.
Step 5: tackle a greasy kitchen line
Grease cools on pipe walls and collects crumbs. After snaking, run very hot water for several minutes. Skip caustic cocktails. Use plain dish soap and heat to move residue along. To prevent new buildup, pour cooled fats into a container and toss in the trash. Many agencies tell residents to keep FOG out of sinks because it hardens in shared lines and triggers blockages.
Step 6: try a wet/dry vac (optional)
Set the vac to wet mode and fit a tight gasket around the drain opening. Cover the overflow. Hold the hose firmly and run the vac for 10–20 seconds to pull debris. This trick shines on hair clogs near the top of the line. Flush with hot water after.
Safety notes you should not skip
Ventilate the room. Wear eye protection whenever you open the trap or use a snake. Never mix drain opener with bleach, ammonia, or vinegar. If you used a chemical opener earlier, flush the line with lots of water before trying anything else. For safe handling of bleach and mixing risks, see the CDC bleach page. For hazards and first aid related to drain openers, the Poison Control drain cleaner page explains what these products contain and why they demand care.
What to do when the trap keeps clogging
Repeat clogs point to a deeper issue. A sagging trap can hold sludge. A tailpiece that sits too low can choke the flow. Some pop-up assemblies leave a shelf where hair collects. Replace sticky parts and set the trap level with a slight pitch toward the wall. Use smooth-wall PVC where allowed; corrugated flex pipe snags debris.
Kitchen sink specifics
Garbage disposal checks
If the disposal hums but doesn’t spin, cut power, then use an Allen wrench in the bottom hub to free the flywheel. Press the reset button and try again. Never put your hand in the chamber. If water backs up on the disposal side, your clog is likely in the branch line, not the unit itself. Snake through the trap arm or the cleanout.
Grease and starch traps
Pasta, rice, and potato peels swell and turn gummy. Coffee grounds settle. Long strings wrap around bends. Catch these at the strainer and bin them. Keep fats, oils, and grease out of the sink entirely. Toss cooled oil and scrape pans before washing so residue doesn’t coat pipe walls.
Bathroom sink specifics
Pop-up tune-up
The pivot rod wears at the ball end and can snag hair. Swap the rod if it’s rough or corroded. Lubricate the strap holes and adjust the clip so the stopper seals but still lifts clear when open. A smooth, full lift helps flow.
Overflow cleaning
Hair and paste can lodge in the overflow channel. After clearing the main drain, feed a bit of snake or a flexible brush into the overflow opening and rinse with hot water. Seal the overflow when plunging so your force goes where it counts.
Step-by-step detail: from easy to invasive
Boiling water flush
Use only on metal or heat-rated plastic sinks. Bring a kettle to a boil and pour in two rounds, a minute apart. Heat softens soap scum and butterfat films. If the line is fully blocked, stop and move to the next step to avoid standing hot water.
Dish soap boost
Squeeze a long line of dish soap into the drain. Wait five minutes. Run hot water. The surfactants help slide grease along. This also primes the line before plunging.
Baking soda and vinegar reaction
Measure one cup of baking soda into the drain. Follow with one cup of warm vinegar and an immediate plug. Wait ten minutes. The fizz can shift light buildup near the top. Rinse with hot water. Skip this if you used any chemical opener.
Plunge, then inspect
After plunging, run water for a full minute. If flow is smooth and quiet, you’re done. If it slows again within a day, move to the trap and snake sequence to get past the near end of the line.
Drain anatomy basics
The stopper or strainer sits at the top. Below it is the tailpiece, then the curved P-trap, then the trap arm into the wall. A vent ties in above the trap arm to admit air. Most clogs live at the stopper or the trap. If you reach ten feet and still meet a hard stop, the blockage may be in the branch line past the vent tie-in.
Troubleshooting odd cases
Double-bowl sinks swap water
When you plunge one side and water jumps to the other, plug the idle bowl. You need a full seal or your force escapes. A baffle tee between bowls can also hold scraps; snaking through the trap arm gets past it.
Air gulping after you fix the clog
A loud slurp at the finish hints at a vent restriction. Roof vents can ice over or collect leaves. If other fixtures also glug or smell, call a pro to check and clear the vent from the roof with proper fall protection.
Rusty or glued traps
Old chrome traps can fuse at the nut. Wrap with a rag to protect the finish and use steady pressure. If your trap was glued, you’ll need to cut and rebuild with slip-joint parts so you can service it next time.
Tool list and when to use each
| Method | Typical time | Risk notes |
|---|---|---|
| Stopper clean | 5–10 min | Keep track of small parts |
| Plunging | 5–15 min | Seal overflow; use steady strokes |
| P-trap clean | 15–30 min | Have bucket ready; re-seat washers |
| Hand auger | 20–40 min | Protect finishes; don’t force bends |
| Wet/dry vac | 10–15 min | Seal well; shield splashes |
Prevention that saves you from the next clog
Catch debris at the top
Use a tight-mesh basket in kitchen sinks and a hair catcher in bathroom sinks. Empty them often. A few seconds here avoids a long session under the cabinet later.
Mind what goes down
Scrape plates into the trash. Wipe greasy pans with a paper towel before washing. Pour cooled oil into a can and toss it. These small habits stop fat films from forming inside your pipes and the shared line.
Rinse with heat
Run hot water after dish duty. A 20–30 second rinse moves soap and fine scraps along. Skip scalding water on PVC unless the maker rates it for heat.
Keep labels and a plan
Store the sink tool kit: plunger, zip-strip, 1/4-inch auger, pliers, spare washers. Tape a simple flow chart on the cabinet door: stopper → plunge → trap → snake. When stress hits, a checklist keeps you calm and on track.
When to call a pro
Bring in a licensed plumber if you smell sewage, see repeated backups across more than one fixture, or your snake meets a hard stop you can’t pass. Camera work may be needed to find a collapsed line or a deep grease plug. Pro gear can also descale old galvanized pipe from the inside to restore flow.
Quick reference: what fixes what
Hair and soap scum
Target the stopper area first. Pull the mat, then plunge. If flow still lags, snake five feet and test.
Grease and food paste
Flush with heat and dish soap, then snake. Keep fats and starches out going forward. Your city or state site will have a FOG page that explains why this keeps both home pipes and shared lines clear.
Foreign objects
Shine a light. If you can see the object near the trap, remove the trap and tip it into a bucket. For items stuck past the trap, a retriever tool or a pro visit is the safer path.