Double sinks are convenient—until one side stops draining. Or worse, both sides back up and you're left with a sink full of dirty water and no way to wash dishes.
The good news: most double sink clogs clear with the same methods used for single-basin sinks. The key difference is knowing which side to target and how to handle the shared plumbing. This guide covers both scenarios.
Describe the problem and get connected to a licensed plumber. Call (833) 567-5795 for fast, professional drain service.
How Double Kitchen Sinks Work
Understanding the setup helps you fix it faster. A double sink has:
- Two basins with separate strainers that empty into tailpieces
- A tee fitting that connects both tailpieces into a single line
- A shared P-trap that catches debris and prevents sewer gas from entering your home
- A shared drain line that runs to the wall and connects to your home's plumbing
The tee fitting is the most common spot for a double sink clog because water from both basins converges there.
Why Your Double Sink Gets Clogged
One Side Clogged
When only one basin is blocked, the problem is in that side's strainer basket or the branch line before the tee. Common causes:
- Food debris caught in the strainer
- Grease buildup in that side's drain line
- A defective or missing strainer basket that lets particles through
- Soap scum restricting flow at the connection point
Both Sides Slow or Clogged
When both basins are affected, the shared plumbing is blocked:
- P-trap clog: The curved pipe under the sink is packed with debris
- Shared line blockage: The tee fitting or horizontal pipe is restricted
- Deeper drain issue: The line running to the wall or beyond is clogged
Double Sink with Garbage Disposal
If one side has a disposal, the blockage is often:
- Grease and food in the disposal chamber
- A clog at the disposal discharge tube connection
- Food packing in the opposite strainer basket
Call a plumber immediately if:
- Water from one side backs up into the other side when you run the disposal
- Both basins overflow despite clearing water
- You hear gurgling from toilets when the sink runs
- There's a sewage smell even after running water
- Water comes up through the dishwasher connection
These indicate a deeper plumbing issue that DIY methods won't fix.
How to Unclog a Double Kitchen Sink
Method 1: Clear Standing Water First
If both sides have standing water:
- Use a cup or ladle to bail water into buckets
- Or use a wet/dry vacuum to remove water from both basins
- Keep at least one side relatively empty for plunging
Method 2: Plunge the Clogged Side
Best for: One side blocked or both slow
Time: 10–15 minutes
- Fill the clogged side with 2–3 inches of water
- Use a cup plunger (flat bottom)
- Block the overflow hole on the clogged side with a wet rag
- Block the good side drain completely with a wet cloth—this is critical
- If you have a disposal, block the disposal opening with a cloth too
- Plunge firmly for 20–30 strokes
- Check if water drains quickly
- Repeat if needed
Still clogged after trying these methods?
Our plumbers have the equipment to clear any double sink blockage fast. Call (833) 567-5795
Method 3: Clean the P-Trap
Best for: Both sides slow or completely blocked
Time: 20–30 minutes
- Place a large bucket under the P-trap
- Loosen the slip nuts on both ends of the trap
- Remove the trap and empty water and debris
- Inspect the trap for grease buildup and clean thoroughly
- Check the wall pipe with a flashlight
- Look inside the tee fitting—if accessible, clear it
- Reassemble hand-tight
- Run water and check for leaks
Most double sink clogs clear with P-trap cleaning.
Method 4: Snake the Drain
Best for: Clogs beyond the P-trap
Time: 20–30 minutes
- Remove the P-trap as described above
- Insert the drain snake into the wall pipe
- Feed the cable while turning clockwise
- Work through resistance until you feel the blockage break
- Pull the snake out slowly
- Reassemble the P-trap
- Flush with hot water
For deep or stubborn blockages, our technicians use motorized equipment that reaches 50+ feet and emergency service is available 24/7.
Fixing a Clogged Garbage Disposal Side
If the disposal side won't drain:
- Run the disposal to see if it hums or jams
- If it hums, it's jammed—use the disposal wrench (hex key) underneath
- If it doesn't run, press the reset button on the bottom
- Turn off power and use tongs to remove debris from the chamber
- Never put your hand inside the disposal
When to Call a Plumber for Your Double Sink
Get professional help if:
- Plunging and P-trap cleaning don't resolve the clog
- Water backs up from one side to the other
- Both sides drain slowly after clearing the P-trap
- You smell sewage or notice other drains are affected
- The clog keeps returning after you clear it
These signs point to a deeper issue in your drain line. Professional drain cleaning uses camera inspection and hydro jetting to fully clear the problem. Call now to schedule service.
Cost to Unclog a Double Kitchen Sink
| Service | Cost | Notes |
|---|---|---|
| DIY (plunging, P-trap) | $0–$20 | If you already own a plunger |
| Professional P-trap cleaning | $85–$150 | Most common fix for double sinks |
| Drain snaking | $150–$300 | For clogs past the P-trap |
| Hydro jetting | $300–$600 | Complete pipe cleaning for severe buildup |
| Camera inspection | $100–$250 | Diagnoses hidden or recurring issues |
Persistent clogs usually mean buildup in the shared drain line. Professional cleaning prevents bigger problems. Request a free estimate.
How to Prevent Double Sink Clogs
- Use strainers in both basins—empty them after each use
- Never pour grease down either drain
- Run hot water for 30 seconds after washing dishes
- Clean strainers daily—food builds up faster than you think
- Never put fibrous foods (celery, corn husks, potato peels) in the disposal
- Weekly: Flush both drains with baking soda, vinegar, and boiling water
Frequently Asked Questions
Why is only one side of my double sink clogged?
The blockage is in that side's strainer basket or branch line before the tee fitting connects to the shared drain. Food debris, grease, or a defective strainer causes single-side clogs. Plunge that side specifically while blocking the good side.
How do you unclog a double kitchen sink with standing water?
First, remove standing water with a cup or wet vacuum. Then, plunge the clogged side while blocking the other side completely. If that fails, remove and clean the P-trap. For deep blockages, use a drain snake or call a professional.
Why is my double sink draining slowly on both sides?
Both sides slow means the shared P-trap or the drain line beyond it is partially clogged. Grease and food particles accumulate at the tee fitting where both lines converge. Professional drain cleaning clears the entire shared line.
Should I use chemical drain cleaners on a double sink?
No. Chemical cleaners can damage pipes, harm garbage disposals, and pose safety risks. Mechanical methods—plunging, P-trap cleaning, snaking—are more effective and safer for your plumbing.
How do I prevent my double sink from clogging?
Use strainers in both basins and empty them daily. Never pour grease down either drain. Run hot water after each use. Clean strainers regularly. Never put fibrous foods or coffee grounds in the disposal. Do a weekly baking soda + vinegar flush.