Quick Answer:
If your kitchen sink now takes much longer to drain, the most common causes are grease and food buildup in the trap or drainpipe, or a partial clog further down the line. Try quick checks and simple cleaning steps first to see if the flow improves before calling a plumber.
Why This Happens
Kitchen sinks get slow because pieces of food, coffee grounds, soap scum and grease stick to the inside of the pipe. Over time those materials narrow the opening and water backs up instead of flowing freely. A loose or clogged P‑trap will slow drainage, and poor venting or a clog further in the home’s drain line can have the same effect. If the issue started after recent work on plumbing, the blockage might be leftover debris from that job — in that case, look into Slow drain after plumbing repair. If only the kitchen sink is affected while other drains are fine, see Slow drain only in kitchen sink.
Step-by-Step What to Do
1. Run a quick water test
Run hot water briefly and observe drain speed. Use a steady stream for 10–20 seconds and watch how fast the sink clears. This helps separate a minor slow-down from a clear clog.
2. Clean the stopper and visible parts
- Remove the sink stopper or strainer and clear out trapped food and gunk.
- Wipe away visible residue with a paper towel or cloth before testing again.
3. Try a plunger
- Block any adjacent drain openings (for double sinks) and fill the sink enough to cover the plunger cup.
- Plunge firmly for a minute, then run water to see if flow improves.
4. Check and clean the P‑trap
- Place a bucket under the trap, loosen the slip nuts, and remove the trap. Expect some water and debris.
- Clean the trap by hand or with a brush, then reassemble and test the drain.
5. Use a hand auger or drain snake if needed
- Feed a short drain snake into the pipe from the sink side and break up or pull out the clog.
- After using the snake, run water to confirm flow.
6. Final test
Run the tap on hot and cold and observe the drain speed. If flow returns to normal, you’ve likely cleared the buildup. If it’s still slow or water backs up into other fixtures, stop and consider professional help.
What Not to Do
- Do not pour grease down the sink. Grease cools and solidifies, creating clogs.
- Avoid repeatedly pouring harsh chemical drain cleaners. They can damage pipes and are dangerous to handle.
- Do not force plumbing parts beyond what you can reasonably loosen—overtightening or breaking parts can make repairs more expensive.
When to Call a Professional
- Water backs up into other fixtures (toilets, tubs, or other sinks).
- Repeated clogs return soon after cleaning, suggesting a deeper problem.
- There is a strong sewage smell, slow drainage housewide, or obvious pipe damage.
- You’re uncomfortable removing the trap or using a snake, or a clog resists basic efforts.
Safety Notes
- Wear gloves and eye protection when handling debris or using tools.
- Put a bucket under the trap before disconnecting it to catch water and avoid spills.
- Do not mix cleaners. Never pour bleach into a drain recently treated with an acidic cleaner.
- If you use boiling water, be careful with PVC pipes—use moderate heat and pour slowly to avoid warping.
Common Homeowner Questions
- How long should a sink take to drain? Ideally a kitchen sink should clear within a few seconds; slower than 20–30 seconds suggests a partial clog.
- Will boiling water clear a grease clog? It can help soften fresh grease, but it often only provides a short-term fix for hardened buildup.
- Can I use store chemical drain cleaners? They may work sometimes but can damage pipes and aren’t recommended for repeated use or where plumbing is old.