A puddle of water forming around your air conditioner is never a welcome sight. Your first instinct might be to panic and reach for the phone to call a technician. But before you spend money on a service call, you should know that the most common cause of AC water leaks is something you can fix yourself in just a few minutes.
Here is what to check and how to fix it—without calling a professional.
Why Air Conditioners Leak Water
Air conditioners naturally produce condensation as they cool warm air. This water is supposed to drain away through a collection system. When that system fails, water ends up where it should not be.
| Component | Function |
|---|---|
| Evaporator coil | Cools the air; produces condensation |
| Drain pan | Collects water dripping from the coil |
| Drain line | Channels water out of the unit |
| Condensate pump | Pumps water out (in some units) |
A leak happens when one of these components is blocked, damaged, or improperly installed.
The Most Common Cause: A Clogged Drain Line
About 90% of AC water leaks are caused by a clogged drain line. Dust, dirt, algae, and mold can build up in the drain line, blocking the flow of water. The water then backs up and overflows the drain pan.
How to Check the Drain Line
| Step | Action |
|---|---|
| 1 | Locate the condensate drain line (usually a PVC pipe near the outdoor unit) |
| 2 | Look for a “T” or access point with a cap |
| 3 | Remove the cap and check for standing water or blockages |
