What to Do When You Find Water Under Your Kitchen Sink
You reach under the kitchen sink for a cleaning product and discover the bottom of the cabinet is wet.
What should you do first?
Don't immediately start taking pipes apart.
Water beneath a sink can originate from several different places, so your first job is to identify the source.
1. Remove Everything From the Cabinet
Clear the cabinet completely.
Dry the area with towels so you can distinguish old moisture from new water.
2. Look Above the Plumbing
Sometimes the water isn't coming from the drainpipe at all.
Check around the faucet base, sink rim, sprayer, countertop, and other areas where water might enter the cabinet.
3. Check the Supply Side
Inspect accessible:
- Faucet supply lines
- Shutoff valves
- Connections
If water appears when the faucet isn't running, investigate the pressurized supply side carefully.
4. Check the Drain Side
Run water while observing the drain assembly.
Look around:
- Sink drain
- Connections
- P-trap
- Drainpipe entering the wall
If water appears only while the sink is draining, this can help narrow down the source.
5. Check Other Equipment
Some kitchen sinks share cabinet space with dishwasher connections, garbage disposal components, water filtration systems, or other equipment.
Don't assume the visible sink plumbing is automatically responsible.
6. Protect the Cabinet
Once the water source is controlled, dry the cabinet thoroughly.
Persistent moisture can damage cabinet materials and create additional problems.
7. Don't Overtighten Everything
If you find a wet connection, tightening it as hard as possible isn't necessarily the correct repair.
The problem may involve a seal, fitting, damaged component, or improper installation.
Diagnose first.
When to Call a Professional
Seek professional assistance if the leak is substantial, concealed, recurring, involves damaged plumbing, or can't be reliably identified.
Final Thoughts
Water under the kitchen sink is a warning.
Don't cover it with a towel and forget about it.
Clear the cabinet.
Dry the area.
Find the source.
Then make the correct repair.
A few minutes of careful investigation can prevent a small leak from becoming a much larger kitchen problem.