When we get a call about an AC leaking water, one of the first things we want to know is where the water showed up and what the system was doing when it happened.
That’s because the puddle itself can tell us quite a bit.
Water underneath the indoor unit often points us toward the condensate drain or drain pan. Water showing up after the AC has struggled to cool may have started as ice on the evaporator coil. And if the AC suddenly stopped working at the same time the leak appeared, a safety switch may have shut the system down before the problem got worse.
So before you grab a towel and assume the worst, take a quick look around.
There are a few things you can safely check yourself, and what you find can help you decide whether you’re dealing with a minor drainage problem or something that requires professional AC repair.
Quick Answer: What Should I Do if My AC Is Leaking Water?
If your AC is leaking water inside, turn it off, clean up any standing water, replace a dirty air filter, and check the condensate drain line for a clog. If you see ice, the leak returns, or water is near electrical components, leave the system off and schedule professional AC service.
Before You Fix Anything, Follow the Water
Your air conditioner is supposed to produce water.
That sounds strange when you’re standing next to a puddle, but condensation is a normal part of the cooling process.
As your AC pulls heat and humidity from the air, moisture collects on the cold evaporator coil. That water drips into a pan and travels through a condensate drain line away from the equipment.
During Montgomery’s long, humid cooling season, your AC can remove a significant amount of moisture from the air every day. That’s why condensate drainage problems often become especially noticeable once summer heat and humidity settle into Central Alabama.
The problem isn’t that your AC is making water.
The problem is that the water isn’t getting where it’s supposed to go.
Before touching anything, turn off the AC if it’s actively leaking and clean up standing water. Then look for a few clues.
Clue #1: There's Water Around the Unit, but the AC Seems to Be Running Normally
This is when we’d start thinking about the condensate drain.
Dust, algae, and other buildup can gradually collect inside the drain line. The AC may continue cooling normally while the drain becomes slower and slower.
Eventually, the water backs up.
Easy Fix #1: Check the Condensate Drain
Look for the condensate drain line running away from your indoor equipment. Depending on your home’s setup, it may terminate outside near the condenser or another drainage point.
If you can safely identify the outdoor drain opening, check for obvious buildup.
A wet/dry vacuum can sometimes pull a minor blockage from the line. Attach the vacuum to the drain outlet, create as good a seal as practical, and run it briefly to pull debris outward.
Then watch the line.
If water begins draining normally again and the indoor leak stops, you may have found the problem.
If the line immediately backs up again, the blockage may be deeper or there may be another drainage issue.
That’s when we’d rather you call Hans than start taking drain fittings and HVAC components apart.
Clue #2: Your AC Isn't Cooling Well and You See Ice
Now we’re looking at a different problem.
If you notice ice on the refrigerant line or around accessible parts of the indoor equipment, the water on your floor may actually be melted ice.
Evaporator coils can freeze when they become too cold. Once that ice begins thawing, the drainage system suddenly has much more water to handle than normal.
One of the simplest causes is restricted airflow from a dirty filter.
Easy Fix #2: Check Your Air Filter and Let the System Thaw
Pull out the air filter and take a look at it.
If it’s packed with dust and debris, replace it with the correct filter for your system.
Then leave the cooling off and give the ice time to thaw completely. Don’t scrape, chip, or pry ice from the equipment. Evaporator coils and refrigerant lines are easier to damage than they look.
Keep towels nearby because you may see additional water while everything thaws.
Once the system is completely thawed and you’ve installed a clean filter, you can try the AC again.
If it freezes a second time, stop there.
A dirty filter isn’t the only reason an evaporator coil freezes. Blower problems, airflow restrictions, and low refrigerant caused by a leak can produce similar symptoms, and those need professional diagnosis.
Clue #3: The Drain Is Clear, but Water Is Still Appearing
If you’ve ruled out a clogged drain and dirty air filter but the AC is still leaking, the drain pan is the next place to look.
The drain pan sits beneath the evaporator coil and catches the condensation your AC removes from the air before directing it into the drain line. Over time, especially as the system ages, the pan can rust, corrode, or develop cracks.
When that happens, the drain line may be completely clear, but the water never makes it there. Instead, it leaks through the damaged pan and collects around the indoor unit.
Easy Fix #3: Inspect the Drain Pan
Use a flashlight and look for:
- Standing water
- Rust or heavy corrosion
- Visible cracks
- Water underneath the pan
- Signs that water is escaping from one particular area
You can remove accessible standing water with towels or a wet/dry vacuum.
What you shouldn’t do is treat that as the repair.
If the pan is damaged, it generally needs to be replaced. Trying to patch a badly corroded HVAC drain pan can simply postpone another leak.
Clue #4: The AC Suddenly Stopped Working When the Water Appeared
Believe it or not, this can actually be a good sign.
Many AC systems have a float switch designed to detect backed-up condensation. When the water reaches a certain level, the switch shuts the air conditioner down before the pan can continue overflowing.
In other words, the system may not have “broken.”
It may have caught the problem before you ended up with even more water on the floor.
Easy Fix #4: Check for a Backed-Up Drain Before Restarting the AC
If the AC stopped and you found water around the same time, look for standing water in the accessible drain area and check the condensate line for a blockage.
Clear any minor, accessible obstruction and remove standing water.
But don’t bypass the float switch just to get the AC running again.
That switch is doing its job. The real fix is figuring out why the water backed up enough to trigger it.
If clearing an obvious drain blockage doesn’t solve the problem, Hans Heating & Air can inspect the drainage system and determine what’s keeping the water from moving properly.
What if None of These Clues Match?
That’s useful information too.
An AC water leak doesn’t always come from a simple clogged drain.
If you’ve checked the obvious possibilities and can’t figure out where the water is coming from, the cause could involve:
- A condensate pump that isn’t working
- A cracked or damaged drain pan
- A frozen evaporator coil
- Low refrigerant caused by a leak
- Blower or airflow problems
- Improper drainage
- Another mechanical issue inside the equipment
This is also where we’d recommend putting down the tools.
You shouldn’t have to dismantle your air conditioner to diagnose a water leak.
When Water Around Your AC Becomes Urgent
A little condensation in the wrong place can turn into a home repair surprisingly quickly.
Water can damage drywall, flooring, ceilings, insulation, cabinetry, and surrounding building materials if the leak continues.
Turn the system off and call for service if:
- Water is near electrical equipment.
- Water is coming through a ceiling or wall.
- The evaporator coil repeatedly freezes.
- The condensate drain keeps clogging.
- The drain pan appears cracked or badly corroded.
- The AC won’t restart.
- The leak returns after you’ve cleared the drain.
- You simply can’t tell where the water is coming from.
There’s no prize for troubleshooting an AC leak until you’ve taken half the system apart.
The easy fixes are worth checking. Beyond those, professional diagnosis is usually the safer move.
One Thing We Wish More Homeowners Knew About AC Drain Lines
Condensate drains are easy to forget because when they’re working correctly, you barely know they’re there.
That’s also why problems can build for quite a while before anyone notices.
A little dust reaches the drain. Algae begins growing. Water moves more slowly. Eventually, a line that seemed perfectly fine last summer can’t keep up with the amount of condensation your AC is producing during another hot, humid Montgomery summer.
Regular AC maintenance gives us a chance to inspect the drainage system before the puddle is what tells you there’s a problem.
FAQs About AC Water Leaks
Can I run my AC if it's leaking water?
No. If your AC is actively leaking water inside, turn it off until you identify the cause. Continuing to run the system can create more condensation, worsen the leak, and increase the risk of water damage around the indoor unit.
Why is my AC leaking water even though the drain line isn't clogged?
If your AC is leaking but the drain line is clear, the problem may be a frozen evaporator coil, damaged drain pan, failed condensate pump, or another drainage issue. If the source isn’t obvious, have the system professionally inspected.
Why is water dripping from my AC vent?
Water dripping from an AC vent can be caused by condensation, poor insulation around ductwork, high indoor humidity, or a drainage problem near the air handler. Because water around vents can also damage ceilings and drywall, persistent dripping should be inspected.
Why is my AC leaking water through the ceiling?
An AC can leak through the ceiling when an attic air handler’s condensate drain becomes clogged, the drain pan overflows, or another drainage component fails. Turn the system off and address the leak promptly to limit damage to drywall, insulation, and ceilings.
Why does my AC smell musty when it's leaking water?
A musty smell near a leaking AC can indicate standing water or excess moisture around the condensate drain, drain pan, or HVAC equipment. Persistent moisture can support microbial growth, so the source of both the water and odor should be corrected.
Found the Water? Now Find Out Why It's There
Your AC naturally produces condensation as it cools your home. The problem starts when that water can no longer drain properly and ends up around your indoor unit.
Where the water appears, whether there’s ice, whether the AC is still cooling, and whether the system suddenly shut down can all help point you toward the cause.
Start with the simple things: turn the AC off, check the filter, inspect the drain, and look for visible ice or standing water.
If your AC is leaking water in Montgomery, Prattville, Wetumpka, or a surrounding Central Alabama community, Hans Heating & Air can find the source and get the system draining properly again.
Schedule AC service with Hans Heating & Air and get the leak handled before your HVAC problem becomes a water-damage problem.