Sink Filling Up With Water Instead of Draining? Fix It Step by Step
Few plumbing problems are as frustrating as a sink that fills up with water instead of draining. Whether it’s in the kitchen or bathroom, standing water is annoying — and sometimes urgent. The good news? Many clogs can be fixed yourself before calling a plumber.
Why Is My Sink Filling Up With Water?
Slow or backed-up drains usually mean a blockage or venting issue. Common causes include:
- Hair and soap buildup
- Grease and food particles
- Clogged or dirty P-trap
- Blocked plumbing vent
Step 1: Remove Visible Debris
Remove the drain stopper and clean out any visible debris like hair or soap using gloves or a drain hook.
Step 2: Pour Hot Water Slowly
Pour hot water (not boiling for PVC pipes) into the drain to dissolve soap or grease buildup. Repeat if needed.
Step 3: Baking Soda + Vinegar Method
This natural method works well for minor clogs:
- Pour ½ cup baking soda into the drain
- Add 1 cup white vinegar
- Cover drain for 15–20 minutes
- Flush with hot water
Step 4: Clean the P-Trap
Remove the P-trap under the sink, empty debris into a bucket, clean thoroughly, and reassemble.
Step 5: Plunge the Sink
Fill the sink with a little water and use a cup plunger. Cover the overflow if present and plunge firmly to dislodge clogs.
Step 6: Check Venting Issues
Gurgling or slow draining may indicate a blocked vent — professional inspection may be needed.
⚠️ When to Stop DIY
- Water backs up into multiple sinks
- Sewer smell present
- Leaks appear under the sink
Call a Plumber When Needed
- Professional drain cleaning
- Pipe damage inspection
- Main line blockage removal