Start with the easy fixes in order: reset or run the disposal, plunge with the second basin blocked, then remove and clean the P-trap, then use a drain snake. Kitchen clogs are usually grease, food and starch. Skip chemical cleaners. If a snake will not clear it, the blockage is farther down the line.
What should I try first?
Start with the disposal, if you have one, because it sits at the front of the drain and is the easiest thing to check.
- 1Check the disposal. Run it again, or reset it if it tripped. InSinkErator's reset page describes a red, square reset button on the bottom of the unit. If it has tripped, the button sits about a quarter inch out. Press it in, wait about ten minutes for the unit to cool (twenty for an EZ Connect model), and try again. Never put your hand into a disposal. If it hums but the blades do not spin, see disposal humming, not working.
- 2Try a plunger. InSinkErator's clogged-disposal page describes a plunger method, using warm water and a little baking soda, for a disposal that is blocked. AAA says "a plunger may be all you need" for many clogs, and that is often the case in a kitchen.
- 3Clean the P-trap. AAA lists checking the trap as a standard step. Put a bucket underneath, loosen the fasteners, remove the trap, and rinse it out.
- 4Snake the drain. A drain auger pushes through clogs beyond the trap.
### How do I plunge a double kitchen sink?
Plunging works by pushing and pulling water through the blockage, and that only works if the pressure has nowhere else to go. A double sink is the problem here, because the second basin gives the pressure a way out.
Block the second drain first, either with its stopper or with a wet rag pressed in tightly. Then put a cup plunger over the clogged drain and add enough water to cover the rubber cup. Pump steadily. Lift the plunger to see whether the water starts to drop. If it does, run hot tap water for a minute to carry the loosened material along.
If you have a dishwasher, check whether it drains through the same side of the sink. Some dishwashers connect to the disposal or to the same tailpiece, and a clog can push dirty water back up into the dishwasher. Our dishwasher not draining page covers that.
What causes kitchen sink clogs?
Grease is the main one. It goes down as a liquid, cools inside the pipe and coats the walls. Food scraps and starch stick to that coating, and the layer grows a little with every meal. Coffee grounds, rice, pasta and eggshells are common culprits, and even a disposal cannot grind them fine enough to stay suspended. Phoenix Water Services says grease is the most frequent cause of sewer line blockages in its service area and roots are the second, which shows how much of the problem starts in the kitchen.
Pouring grease down the drain and following it with hot water does not fix the problem. It moves the grease farther down the line, where it cools and sticks. Wipe pans with a paper towel and throw the towel away instead. Our what not to put down the drain page has the full list.
Should I use a chemical cleaner?
No. Delta Faucet notes that hair, soap and cleaning products build up inside pipes, and a kitchen adds grease to that list. A caustic cleaner that does not work leaves a sink full of harsh liquid, and you then have to plunge or work through it. AAA's own guidance is a set of strategies that work without chemicals. Our safe alternatives page has the gentler options.
A word on boiling water. AAA cautions that boiling water can melt debris and create a second clog farther down, or cause pipes to expand and leak. Very hot tap water is a safer choice.
### What if the sink drains but slowly?
That is an early stage of the same problem. The pipe is narrowing, and the water is telling you about it. See how to fix a slow-draining sink and disposal draining slow. A slow drain is much easier to clear than a full stop, so this is the best time to act.
### Why does a kitchen sink need a trap at all?
The curved pipe under the sink is there on purpose. The 2024 International Plumbing Code, in Chapter 10, requires each fixture to be separately trapped, and the water seal in a trap is between 2 and 4 inches deep. That standing water blocks sewer gas from entering the house. It is also why the trap is the first place debris collects, and why it is worth cleaning out by hand before reaching for tools that go deeper.
How do I keep it from clogging again?
Prevention in a kitchen comes down to what goes in the drain, and it is mostly about grease and food scraps. Once a clog is cleared, a few habits keep it from returning.
Scrape plates into the trash. Food scraps, rice, pasta and coffee grounds are easier to throw away than to clear later. A disposal grinds food, but it does not make grease or starch behave.
Wipe greasy pans first. A paper towel takes most of the grease off a pan. What is left is small enough to go down with dish soap and warm water. Pouring grease into a can and throwing it away keeps it out of the pipe entirely.
Run water with the disposal. Run cold water while the disposal is on, and for a few seconds after, so the ground material is flushed well past the trap. Check your disposal's manual for its own directions.
Use a drain strainer. A basket strainer in the sink catches what the disposal does not need to see. Empty it into the trash after each meal.
Flush with hot tap water once a week. A minute of hot tap water after washing dishes carries soap and light grease along before it hardens. Use tap water, not boiling water, for the reasons AAA gives above.
Do not ignore a slow drain. Slow drains are the warning stage. Clearing the trap at that point takes a few minutes and prevents the full stoppage that usually arrives on a holiday weekend.
If a clog keeps coming back within days of clearing it, the cause is usually farther down the line, and it is worth reading why the same drain keeps clogging.
When should I call a plumber?
Call if the snake does not clear it, since the blockage may be farther down than you can reach. Other signs are more than one slow fixture, water coming up in another drain, or a gurgling sound from a drain when you run water elsewhere. Our main line vs branch clog page explains how to tell. Phoenix Water Services says the owner is responsible for the line from the house to the city main, and that is where a deep blockage often sits.
HQ Plumbing & Air is licensed and insured, gives free estimates and upfront pricing, and answers 24/7. If something small fell in, see get something back that fell down the drain. For leaks, disposals and dishwasher drains, see our roundup of common kitchen plumbing problems.