A kitchen sink that clogs once is an annoyance. A kitchen sink that clogs every few weeks is telling you something. Either something keeps going down the drain that shouldn’t, or the pipe itself has narrowed and catches everything that passes through.
Here’s what usually causes it, what you can try on your own, and when it’s time to call a plumber.
The usual suspects
Most repeat kitchen clogs come down to a few things:
- Grease and oil. It goes down as a liquid, cools in the pipe and sticks to the walls. Every rinse adds a layer. Over months, a 2-inch pipe can shrink to the size of a pencil.
- Coffee grounds and eggshells. They don’t dissolve. They settle into the grease and act like gravel.
- Rice, pasta and potato peels. Starchy foods swell with water and turn into paste.
- Fibrous scraps. Celery, onion skins and corn husks wrap around garbage disposal blades and slip past them in long strands.
- Hard water. Tri-Valley water is hard. Mineral scale builds up inside older pipes and gives grease something rough to cling to.
Where the clog usually is
Water from your kitchen sink passes through a few parts before it joins the rest of your plumbing:
- The garbage disposal and the P-trap under the sink.
- The drain arm that goes into the wall.
- The kitchen branch line that runs through the wall and under the floor, usually shared with the dishwasher.
Most repeat clogs are in that branch line, where grease cools and builds up out of reach. Signs the clog is in the line, not just the trap:
- Water backs up into both sides of a double sink.
- Dishwasher water comes up into the sink.
- The sink still drains slowly or gurgles after you clean the trap.
- The clog comes back in the same spot, usually after big meals or holidays.
What you can safely try first
For a kitchen-only clog:
- Check the disposal. Turn off power, then use the hex key on the bottom of the unit to free it up. Press the reset button.
- Use a sink plunger. If you have a double sink, plug the other side first so the pressure goes toward the clog.
- Clean the P-trap. Put a bucket underneath, unscrew the curved pipe under the sink and clear it out.
- Run hot water, not boiling. Boiling water can soften PVC joints.
Skip the chemical drain cleaners. They rarely clear grease clogs, they can damage older metal pipes, and they make the job dangerous for whoever has to open the line next.
Why it keeps coming back
If you clear the clog and it returns in a few weeks, the pipe is the problem, not the last thing you put down it.
Many Tri-Valley homes built in the 1960s and ’70s still have galvanized steel or cast iron drain lines. Those pipes rust and scale from the inside, which leaves a rough, narrow passage that grease builds up on quickly. A standard drain snake pokes a hole through the clog, but it leaves most of the buildup on the pipe walls. The clog comes right back.
That’s when we recommend a camera inspection to see what’s going on inside the pipe, and often hydro jetting to scrub the walls clean. Learn more about our drain cleaning service.
How Barnett Plumbing helps
When you call us about a kitchen clog, we’ll:
- Clear the clog and tell you what caused it.
- Clean the whole kitchen line when buildup is the problem, not just punch a hole through it.
- Run a camera down the line if the clog keeps coming back, so you can see the pipe for yourself.
- Explain your options before any work starts.
We’ve been clearing drains in Livermore, Pleasanton, Dublin, San Ramon, Danville and the rest of the Tri-Valley since 2005.
Kitchen sink clogged again? Call us at (925) 872-0805 or book online.
