Key takeaways
- A clogged condensate drain line is the most common cause of an indoor AC leak.
- A dirty filter or low refrigerant can freeze the coil, which then drips as it thaws.
- Turn the system off if water is pooling near electrical parts, then call for service.
- Routine maintenance clears the drain line before it backs up in peak summer.
Finding a puddle near your indoor air handler is alarming, especially in the middle of a Sacramento heat wave when you need the AC most. The good news is that most AC water leaks trace back to a few common, fixable causes.
Quick answer
Most indoor AC leaks come from a clogged condensate drain line, a full drain pan, a dirty filter that froze the coil, or low refrigerant. Replace the filter, clear the drain if you can, and if water keeps coming, shut the system off and call a technician.
1. A clogged condensate drain line
Your AC pulls humidity out of the air, and that moisture drains away through a condensate line. Over time, algae and dust clog that line, so water backs up and overflows the pan. This is the single most common cause we see on service calls.
The fix: a wet/dry vacuum on the outdoor end of the drain often clears it. If it keeps clogging, a technician can flush it and add a treatment tablet.
2. A rusted or cracked drain pan
On older systems, the pan that catches condensation can rust through or crack, letting water drip straight onto the floor. Pans on units 12 or more years old are especially prone to this.
The fix: the pan needs replacement, which is a quick job for a technician.
3. A frozen coil that is thawing
A dirty filter or low refrigerant can drop the evaporator coil below freezing. Ice builds up, then melts all at once and overwhelms the drain pan. If you see ice on the lines, this is likely your culprit. Our guide to an AC that won't cool covers freezing in more detail.
The fix: turn the system off, run the fan to thaw it, replace the filter, and if it refreezes, call for service.
How to prevent AC leaks
- Change your filter on schedule, especially during our long cooling season.
- Get an annual tune-up that includes a drain-line flush.
- Keep the area around the indoor unit clear so you spot moisture early.
Water where it shouldn't be?
We will find the source and fix it fast, with service across Greater Sacramento.
