What is the first thing to try on a clogged kitchen sink?

Hot water and a plunger, in that order, before anything harsher. A kettle of near-boiling water poured in two or three stages often softens a grease clog enough to restore flow on a slow drain — but skip this on a fully blocked sink with standing water, and go easy on older PVC. If hot water does not clear it, plunge with a cup plunger, blocking the other basin in a double sink. The great majority of kitchen clogs are grease and food in the P-trap, which these two steps or a trap cleaning will clear.

Should I use chemical drain cleaner on a kitchen sink?

Avoid it, especially on a fully blocked drain. Caustic and acidic cleaners generate heat that is hard on older PVC and metal traps, they are ineffective when standing water dilutes them or the clog is solid grease, and they leave a caustic pool that becomes a hazard for whoever opens the trap next. Mechanical methods — hot water, a plunger, cleaning the P-trap, and a drain snake — solve the actual clog without the risk. If you use anything, an enzyme maintenance product is gentler, but it is slow and works as prevention, not a fix.

Why does my double kitchen sink back up on both sides?

Because both basins share a single trap and drain downstream of the tee that joins them, so a clog past that junction backs up into both bowls. When you plunge one side, water and pressure escape up the other basin unless you block it — stuff a wet rag into the second drain or have a helper hold a stopper and a plunger over it. The shared clog is usually in the P-trap or the branch drain beyond it; cleaning the trap or snaking the branch line clears both sides at once.

How do I clean a kitchen sink P-trap?

Place a bucket under the trap, loosen the two slip nuts by hand or with pliers, and lower the U-shaped trap into the bucket — it is usually full of grease and food, which is the clog. Clean it out, check the trap arm going into the wall for buildup too, and reassemble with the washers oriented correctly (bevel toward the joint). This is a 15-minute job and clears an enormous share of kitchen clogs because the low bend of the trap is exactly where grease and debris settle.

When should I call a plumber for a kitchen sink clog?

Call a pro if you have cleaned the trap and snaked the branch line and it still backs up, if more than one fixture is affected at the same time (a main-line issue), or if water backs up into the sink when the dishwasher or washing machine drains, which points to a shared blockage downstream. A single stubborn kitchen clog you cannot reach with a hand snake may be deeper in the branch line. Repeated grease clogs can also mean a partially collapsed or heavily scaled line that a camera inspection would reveal.

How to Clear a Clogged Kitchen Sink: The Order That Works

Written & researched by Priya Anand DIY & Tools Editor

Updated August 2026

Overhead view of a person's hands tightening a fitting under a kitchen sink with a wrench, in warm evening lamplight

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Clearing a clogged kitchen sink is a DIY job in nearly every case — 15 to 45 minutes, under $30 in tools, no permit. The clog is almost always grease and food in the P-trap. Work in order: hot water, then a plunger, then clean the P-trap, then snake the branch line — and skip the chemical cleaners. The one time to call a pro is when multiple fixtures back up together or the clog survives a cleaned trap and a snaked line, both of which point past the kitchen branch into the main.

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How to Unclog a Kitchen Sink — The Home Depot

Tools and materials

A cup plunger (flat-bottomed, for a sink).
A bucket and towels for cleaning the P-trap, plus channel-lock pliers.
A drain snake for clogs past the trap.
A kettle of hot water and rubber gloves. More tools in best plumbing tools.

Three-quarter view of a person's hands tightening a fitting under a kitchen sink with a wrench, in soft early-morning light

Step 1: Hot water (for a slow drain)

If the sink is draining slowly rather than fully blocked, pour a kettle of near-boiling water down in two or three stages, pausing between. This often melts enough congealed grease to restore flow. Do not do this on a fully blocked sink with standing water — you cannot reach the clog and you risk splashing hot water back — and go gently on older PVC.

Step 2: Plunge

Fill the basin with an inch or two of water to seal the plunger cup. In a double sink, block the other drain with a wet rag or a helper holding a stopper, or your force escapes up the second bowl. Plunge firmly a dozen times keeping the seal; the suction on the up-stroke often breaks a clog the push could not.

Three-quarter view of a person's hands tightening a fitting under a kitchen sink with a wrench, in soft overcast light

Step 3: Clean the P-trap

If plunging fails, the clog is likely in the trap. Put a bucket underneath, loosen the two slip nuts, and lower the P-trap into the bucket. Expect it to be packed with grease and food — that is the clog. Clean it out, check the trap arm going into the wall, and reassemble with the washers' bevels toward the joints. Run water to confirm.

Step 4: Snake the branch line

If the trap was clear and it still backs up, the clog is farther down the branch. Remove the trap and feed a drain snake into the wall stub, cranking clockwise with gentle pressure until you break through, then withdraw slowly. Reassemble and flush with plenty of hot water — a grease clog often needs a second pass.

Close-up detail of the material being worked in a diy plumbing project, in soft overcast light

Step 5: Prevent the next one

Keep grease, coffee grounds, and fibrous or starchy scraps out of the drain — they are the top causes of kitchen clogs. Wipe greasy pans before washing, run cold water when using a disposal so fats stay solid and get chopped, and flush the drain with hot water periodically. Prevention is far easier than clearing.

Common mistakes

Reaching for chemicals first, which rarely clear a grease clog and make later steps hazardous.
Plunging a double sink without blocking the other basin.
Pouring boiling water into a fully blocked, standing sink.
Reassembling the P-trap with a washer backward, causing a new leak.

When to call a plumber

Call a pro if the clog survives a cleaned trap and a snaked branch line, if multiple fixtures back up together (a main-line blockage), or if the sink backs up when the dishwasher or washing machine drains. Repeated grease clogs can signal a scaled or partly collapsed line that needs a camera inspection or a powered auger. Clearing a drain needs no permit, but main-line work is a different matter.

How to Clear a Clogged Kitchen Sink