What can I do if my sink is clogged?
Do these in order. Each one is quick.
1. Stop running water into it. A full basin only gets fuller, and every gallon you add makes the cleanup under the cabinet worse.
2. Bail the basin down into a bucket if you plan to open the trap.
3. Look at the stopper (bathroom sink only). The pop-up stopper hangs on a pivot rod, and hair wraps the rod and the stopper body. Many bathroom sinks let you lift the stopper straight out, and some need the pivot nut behind the tailpiece loosened first.
4. Plunge it. Use a flat-bottom cup plunger, not the flanged toilet kind. Block the overflow slot at the top of a bathroom basin with a wet rag so the pressure goes down the drain and not out of the slot. In a double kitchen sink, plug the other bowl, and close off the dishwasher line if you can. Keep a couple of inches of water over the cup and push in firm, even strokes. If you hear the water gurgle and then drop, the clog was close.
5. Clean the P-trap. This is the U-shaped bend under the sink, and it is the single most useful thing you can do.
How to unclog a sink with standing water
Standing water is a good sign in one way: it tells you the clog is close to the drain opening or in the trap, because water that cannot pass a blockage stacks up behind it. Bail the water into a bucket first, since you cannot work on a full sink. Then plunge, and if the water does not drop within a few strokes, move to the trap. Do not pour a chemical opener into standing water. The liquid sits on top of the clog, cannot be rinsed away, and is still active when you open the trap later.
Unclog a sink drain by cleaning the P-trap
The trap holds a plug of water that blocks sewer gas from the room. It also catches whatever is heavy enough to drop out of the flow, which is why it clogs.
1. Set a bucket under the trap. There will be standing water and sludge in it.
2. Loosen the two slip nuts, one on each end of the U, by hand if you can and with channel-lock pliers if you cannot. Turn them counterclockwise.
3. Slide the trap off, empty it into the bucket, and clear it with a bottle brush or an old toothbrush. Look through it at a light. You should see a clean tube.
4. Check the washers. A cracked or hardened one will leak.
5. Reassemble with the nuts snug by hand, then a small extra turn with pliers, then run water and watch every joint with a dry paper towel held against it.
Plastic traps are easy. Older metal traps can be corroded to the point that the nut will not turn, or the metal crumbles in your hand. If that happens, stop. A trap that breaks while you are holding it has turned a cleaning into a repair.
Why is my sink not draining but the P-trap is clear?
If the trap is clean and the sink still drains slowly or not at all, the blockage is in the trap arm (the short pipe that runs into the wall) or beyond it, or the vent is restricted. Other signs point the same way. A gurgle from the drain after you run water, a toilet bubbling, or water that drains and then creeps back up all say the problem is downstream of the sink. Clean the stopper once more, because a stopper with a hair-wrapped pivot rod can slow a bathroom basin even when the pipe is open. After that, the next tool is an auger.
How does a sink snake work, and where does it stop?
A hand auger (a coil of cable on a crank, often called a sink snake) goes in where the trap clog turned out to be farther in.
1. Remove the trap, as above, and feed the cable into the wall pipe, not down the drain opening. Going through the drain opening means the cable has to bend through the tailpiece and the trap, and it rarely makes it.
2. Push until you feel resistance, then tighten the setscrew on the drum so about a foot of cable sticks out.
3. Crank clockwise while pushing gently. A soft clog feels like a spongy resistance that gives. A hard stop that does not give is a joint, a bend or a solid object.
4. Pull the cable back slowly. What comes out tells you what you had: hair and soap, a gray paste of grease and food, or nothing at all.
Be realistic about reach. A hand auger gets you the first several feet of pipe. If the cable runs its full length and you pull out nothing, the clog is farther in than the tool goes, or the cable is curling back on itself. Forcing a light cable kinks it, and a kinked cable stuck in a wall is its own problem.
How to unclog a sink without a plunger or a snake
Without either tool, the trap is still the answer, because it needs only pliers and a bucket. For a bathroom basin, a thin barbed plastic strip pushed down past the stopper opening pulls up hair from the first few inches of pipe, and that is the right tool when the clog is hair near the top. It does not reach a clog past the trap, and it does nothing for grease. A bent wire hanger is a poor stand-in. It can scratch the drain body and snag in the trap, and it pushes a clog as readily as it pulls one, so use the strip or the trap instead.
Why will my kitchen sink not drain with two bowls?
A double-bowl kitchen sink shares one trap arm, and where the water is standing tells you a great deal. Run the faucet and watch both bowls.
- Only one bowl is backed up. The restriction is in that bowl's own drain, its tailpiece or the trap beside it. Clean that side first.
- Both bowls hold water. The restriction sits past the point where the two drains join, so the trap under one bowl will not fix it.
- Dishwasher water appears in the sink. The dishwasher drain ties into the same line, so the clog is downstream of both.
Kitchen lines clog differently from bathroom lines. The soft, gray paste you pull out is grease that cooled and packed in with food scraps, and it coats the whole pipe, not just the trap. Your auger may open a channel through it, the sink drains, and a month later it slows again.
Kitchen sink clogged and the snake does not work
When a snake does nothing in a kitchen sink, it is one of these:
- The auger went in the drain opening and curled in the trap instead of reaching the blockage.
- The cable is too light for a grease-coated line and bends instead of cutting.
- The clog is past the reach of a hand-crank cable, so the cable runs out before it gets there.
- The sink is fine and the line it empties into is blocked, which a sink snake cannot reach.
That last one matters. If a bathtub gurgles when the kitchen sink drains, or washer water shows up in a floor drain, the problem is not the sink at all.
Kitchen sink will not drain and the garbage disposal is not working
If the sink has a disposal and the disposal hums, stays silent or grinds with the water still rising, work out which side the problem is on before you open any pipe. A jammed grinder and a blocked line downstream look the same from the top. Our page on a garbage disposal that is not draining sorts the two apart, and it covers the reset button and the hex key socket under the unit.
Does hot water, boiling water or dish soap unclog a sink?
Hot tap water melts a fresh smear of grease near the drain and helps a trap that is only slightly slow. Boiling water is a poor idea. Plastic drain pipe is rated by at least one major manufacturer for operating temperatures not over 140 degrees Fahrenheit, and boiling water is 212, so a full kettle can soften joints in a plastic trap. It also does not move a hair clog. Dish soap makes the water slicker and can help a thin grease film move, but it does nothing to a plug of hair or a packed paste, and it will not push through a standing-water clog.
Can baking soda and vinegar unclog a sink?
Baking soda followed by vinegar fizzes and looks like work. It can loosen a thin film of soap near the top of the drain and freshen the smell a little. It does not dissolve a hair clog, it does not cut a grease mat, and it cannot push through a solid plug. On a sink that holds water, skip it and go to the trap, because the fizz just sits there.
Why does it smell bad under my sink?
A smell under the sink comes from a short list of places:
- A dry or siphoned trap. The water seal is gone, so sewer gas comes up the pipe. Run water for half a minute to refill it.
- Food and slime inside the trap or the disposal. Cleaning the trap fixes it.
- A leaking slip nut or washer that drips onto the cabinet floor and goes sour. Look for a damp or stained spot.
- A dishwasher drain hose with standing water in a low loop.
- A vent problem. If the smell comes and goes and the sink gurgles, the vent may be blocked. Our page on a sewer smell in the house goes through the sources.
What is the best drain cleaner for a kitchen sink?
There is no safe chemical shortcut. Store openers are caustic or acid, and a blocked pipe is the one place they cannot spread out and do their work. Enzyme cleaners, such as Green Gobbler, are sold as maintenance treatments to help keep film from building up, not as openers for a sink that is already full, and they do nothing for a solid plug. The better answer is mechanical: a plunger, a clean trap, and an auger. Never mix two products. If you have already put one in, wear eye protection and gloves before you plunge, snake or open anything, because the liquid in the pipe is still active. If the sink has a disposal, read our page on putting drain cleaner in a garbage disposal first.
When should I stop and call a plumber?
Stop and bring in a professional if any of these are true:
- You cleaned the trap, ran an auger through the trap arm, and the sink still holds water.
- Both bowls of a double sink are standing full.
- Another fixture gurgles, bubbles or backs up when the sink drains.
- Water or sewage comes up in a tub, shower or floor drain.
- The sink clogs again within weeks of being cleared.
- You poured a chemical opener and it did not work.
- The trap or slip nuts are corroded and will not move without breaking.
For a stubborn sink, our clogged sink page covers how a kitchen line and a bathroom line fail, and the drain snaking page explains which cable machine fits which pipe. When it keeps coming back, clogged drain repair and hydro jetting cover clearing the whole pipe wall. Several fixtures backing up together is a main-line problem. Stop using water and call.
What it costs
Clearing a single branch line, one fixture and not a main line clog, is covered by our $59 drain cleaning special. Past that, what moves the price is which fixture is involved, whether there is a cleanout or other way in, whether the line needs a cable or jetting, and whether the trouble sits in the branch or the main. We diagnose first, then hand you a flat price in writing that you approve before anything starts. It is a flat rate and not an hourly meter, and on-site estimates are free.
Why is my sink not draining but the pipes are clear?
If the trap is clean, the blockage is in the trap arm or farther into the wall, or the vent is restricted. A gurgle, or water that drains and then creeps back, points downstream of the sink.
Why do both sides of my double sink fill up?
The two bowls join before the trap arm, so water standing in both means the blockage is past that junction.
Is a kitchen sink that will not drain an emergency?
Not by itself, as long as the water is staying in the sink. Stop adding water, and call at once if sewage or dirty water comes up in a tub, shower or floor drain, or if several fixtures back up together.
Is it safe to snake a drain after pouring in a chemical opener?
Only with eye protection and gloves, because the liquid is still active and can splash when you open the trap or run a cable. Never add a second product on top of the first.
Where we work
American Rooter & Drain was established in Caldwell, Idaho in 1945 and has worked the greater Treasure Valley since 1945. We snake drains in Boise, Nampa, Caldwell, Meridian, Kuna, Eagle, Star, Middleton, Garden City, Emmett and the rest of the valley, plus Ontario, Nyssa and Vale in Oregon. See what we do in Boise, Nampa, Caldwell and Meridian. Call (208) 366-5771, days, nights, weekends and holidays.
