Why Is My Air Conditioner Leaking Water? 3 Common Causes

Pools are great. But if it looks like your home is trying to start one indoors—especially around your air conditioning unit—that’s a sign something’s gone sideways. An AC leak isn’t just inconvenient; it can lead to costly water damage, mold growth, and a serious dip in your home’s energy efficiency.

At Radiant, we help homeowners stop air conditioning leaks before they spiral into bigger problems. Here’s what you need to know about why your AC might be leaking water—and what you can do about it.

1. Clogged Drain Line

This is the number one cause of AC leaks. Your air conditioner pulls humidity from the air and sends it out through a condensate drain line. When that line gets clogged with dust, algae, or debris, water backs up and overflows—right into your home.

If you’re noticing puddles or moisture near your indoor unit, this might be the culprit.

2. Disconnected Drain Line

Even if your drain line isn’t clogged, it could be loose or improperly installed. Over time, vibration and pressure can cause it to disconnect, allowing condensation to leak out every time your AC runs. It’s a small issue that can lead to big messes if ignored.

3. Damaged or Cracked Drain Pan

The drain pan is meant to collect condensation, but if it’s rusted, cracked, or damaged, it can’t do its job. Water will leak right through, sometimes slowly enough to go unnoticed—until the damage is done.

Other components can wear out too. A damaged evaporator coil or broken seal can also cause water to leak where it shouldn’t.

What to Do About an AC Leak

If you spot water around your air conditioner, don’t wait. Small leaks can quickly turn into big headaches. Our licensed HVAC technicians at Radiant will inspect your system, identify the root cause, and get your AC back to running clean and dry—fast.

We’ve been fixing leaks (and everything else HVAC) since 1999, with expert service and honest pricing that keeps your home running smoothly, no matter the season.