A kitchen sink that will not drain is one of the most common plumbing headaches we hear about. The good news is you can clear most kitchen clogs yourself with a few simple steps. The trick is knowing which methods actually work and when the clog is too deep to handle on your own.
Below is a step-by-step guide to clearing a slow or stopped kitchen sink, plus the signs it is time to call a plumber in Milton and Halton Region.
Why Your Kitchen Sink Won’t Drain
Kitchen clogs almost always come down to one thing: grease. It pours in as a warm liquid, then cools and sticks to the pipe walls like candle wax. Food scraps, coffee grounds, and soap scum collect on that greasy layer until water barely passes.
Most kitchen sink clogs sit in the trap, the curved pipe under the sink, or in the line just past it. That is good news, because those spots are reachable. A deeper clog in the main line is a different problem, and we will cover how to tell the difference.
Try These Fixes First
Work through these in order. Start gentle, then step up if the clog holds. Skip the chemical drain cleaner, since it rarely clears a grease clog and can damage older pipes.
1. Boiling water
If the sink drains slowly rather than not at all, start here. Boil a kettle and pour the hot water straight down the drain in two or three stages, with a short pause between each. The heat can melt a soft grease clog and flush it through. Do not use boiling water if you have PVC pipes that connect with plastic fittings, since very hot water can soften them.
2. Plunge it
A flat-bottom sink plunger works well on a full stop. Fill the sink with a few inches of water to seal the plunger. If you have a double sink, plug the other drain with a wet rag so the pressure goes down the clog instead of out the second side. Plunge firmly for 20 to 30 seconds, then check the flow.
3. Baking soda and vinegar
Pour half a cup of baking soda down the drain, then half a cup of white vinegar. Let it fizz and sit for 15 minutes, then flush with hot water. This is gentle and can loosen light buildup. It will not break through a heavy grease clog, but it is worth a try before you go further.
4. Clean the P-trap
This is the step that clears most stubborn kitchen clogs. Put a bucket under the trap to catch water. Unscrew the two slip nuts on the curved P-trap by hand or with pliers. Pull the trap off and clear out the gunk inside. This is where grease and food scraps love to collect. Reattach it, then run water to check.
5. Use a drain snake
If the trap was clear but the sink still backs up, the clog is further down the line. A small hand auger, or drain snake, can reach it. Feed it into the pipe, crank until you feel the blockage, then work it through and pull it back out. Run hot water to flush what is left.
When DIY Isn’t Enough
If you cleared the trap and snaked the line and the sink still will not drain, the clog is deeper than a home tool can reach. At that point, more plunging just wears you out.
A few signs point to a problem past the fixture. More than one drain is slow at the same time. The sink gurgles, or water backs up in another fixture when you run it. You hear bubbling from the dishwasher or a nearby drain. These mean the clog is in the branch line or the main line, not the trap.
That is when a professional drain cleaning makes sense. We use a proper drain snake to reach and clear the blockage at the source, not just the surface. For a stubborn or repeat clog, a camera inspection shows exactly what is going on inside the pipe.
Why It Keeps Happening
Clearing the clog feels great until it comes back next month. A kitchen sink that clogs again and again has a cause you have not fixed yet, usually grease coating the pipe walls.
To break the cycle, keep these out of your drain:
- Cooking oil, bacon fat, and grease of any kind
- Coffee grounds and eggshells
- Rice, pasta, and starchy food that swells with water
- Fibrous scraps like celery and potato peels
Let grease cool, then scrape it into the trash. Wipe greasy pans with a paper towel before washing. If your sink still clogs on a schedule, read our guide on why your drain keeps clogging to get to the root of it.
What a Plumber Charges to Clear It
A professional drain cleaning costs less than most people expect, and far less than a flooded cabinet under the sink. Drain snaking starts at about $99. A typical full drain job runs $250 to $350, depending on the location and how bad the blockage is.
You get a flat quote before we start, so there are no surprises. For a full breakdown of what plumbing work costs in our area, see our Milton plumbing cost guide.
When to Call
Try the steps above first. Most kitchen clogs clear with a plunge and a trap cleaning. But some are your sign to put the tools down and call.
Call a plumber when:
- The sink still will not drain after you clear the trap and snake it
- More than one drain is slow or backing up at once
- The sink gurgles or backs up into the dishwasher
- The clog comes back within a few weeks
- You smell sewage near the drain
We serve Milton, Georgetown, Acton, Oakville, Burlington, and the rest of Halton Region, with 24/7 help if a clog turns into a backup after hours. Call us at (289) 367-8218 or request a free estimate and we will clear it fast and tell you what caused it.
Frequently Asked Questions
How do I unclog a kitchen sink that won’t drain?
Start with boiling water if it drains slowly, then try a plunger for a full stop. If that fails, clean out the P-trap under the sink, which is where most kitchen clogs sit. If the trap is clear, a small drain snake can reach a clog further down. Skip chemical drain cleaners, since they rarely clear grease and can harm older pipes.
Why won’t my kitchen sink drain even after I plunge it?
If plunging does not work, the clog is likely past the trap in the branch or main line. Cleaning the P-trap clears many of these. If the trap was clear and the sink still backs up, the blockage is deeper than a plunger can reach and needs a drain snake or a plumber.
Are chemical drain cleaners safe for a kitchen sink?
Not really. They rarely break through a grease clog, the most common kitchen blockage, and the harsh chemicals can soften or damage older pipes. They also make the next plumbing visit messier and more dangerous. A plunger, a trap cleaning, or a drain snake is safer and more effective.
How much does it cost to clear a clogged kitchen sink in Milton?
Drain snaking starts at about $99, and a typical full drain job runs $250 to $350 depending on the location and severity. A camera inspection may be added for a stubborn or repeat clog. You always get a flat quote before any work begins.
Why does my kitchen sink keep clogging?
The usual cause is grease coating the inside of the pipe, which catches food scraps and coffee grounds until water barely passes. Clearing the surface clog leaves that greasy layer behind, so it comes back. Keeping grease, coffee grounds, and starchy scraps out of the drain breaks the cycle. A professional cleaning removes the buildup at the source.