Water leaking from your AC usually means the condensate system is failing: a clogged drain line is the most common cause, followed by a frozen evaporator coil, a rusted drip pan, or a broken condensate pump. Turn the system off first to limit water damage, check the filter and drain line, and call for repair if water returns. Don't keep running a leaking AC.
On this page:
What to Do Right Now
The 6 Reasons Your AC Leaks Water
Can I Keep Running It?
Preventing the Next Leak
FAQs
An air conditioner in a South Florida summer pulls gallons of water out of the air every single day. All of it is supposed to leave through one modest drain line.
When you find water where it shouldn't be, that system has failed somewhere along the chain. The good news: the failure points are few, each leaves a distinct clue, and the most common one is often a DIY fix.
What to Do Right Now (Before Anything Else)
1. Turn the system off at the thermostat. Every minute a leaking AC runs adds water to your floor or ceiling, and if ice is involved, running strains the compressor too.
2. Contain the water. Towels around the air handler, a bucket under active drips, and move anything vulnerable. If water is coming through a ceiling below the unit, that's drywall you're saving.
3. Check the air filter. A matted filter chokes airflow and freezes the coil, and the leak you're seeing may be that ice melting. Replace a dirty filter now.
4. Look for ice. Frost on the refrigerant lines or the indoor coil confirms a freeze-up. Leave the system off and let it thaw completely; running it frozen risks the compressor.
5. Wet/dry-vac the drain line. Find the condensate outlet outside (a small PVC pipe near the outdoor unit), seal a wet/dry vacuum to it with a rag or tape, and pull for a minute or two. This clears the most common blockage on the spot, and our step-by-step guide to unclogging your AC drain line walks through it.
If the leak stops and stays stopped, you've likely solved it. If water returns, one of the six causes below is still active.
6 Reasons Your AC Is Leaking Water
1. Clogged Drain Line
The number-one cause, and in South Florida it's not close. The condensate line is dark, damp, and warm year-round here, which makes it a greenhouse for the algae and sludge that eventually seal it shut. Water backs up the line, fills the pan, and overflows at the air handler.
The tell: water pooled at the indoor unit, often with a musty smell, on a system that otherwise cools normally. The fix: the wet/dry-vac clearing above, plus the prevention flush in the last section.
2. Frozen Evaporator Coil
When airflow is starved (usually a dirty filter) or refrigerant is low, the indoor coil gets too cold and ices over. The "leak" is that ice melting into more water than the pan can handle.
The tell: the leak appears after the system shuts off, and you find frost on the lines or coil. The fix: thaw fully and replace the filter. If ice returns with a clean filter, stop: that points to refrigerant or a deeper airflow problem, both professional territory. Our guide on what to do if your AC freezes up covers the full sequence.
3. Rusted or Damaged Drip Pan
The pan under the coil catches everything the drain line carries away. On systems 12–15 years old, pans rust through, and then even a healthy drain can't help: water pours through the hole instead.
The tell: steady dripping from the pan area on an older unit, even when the drain line runs clear. The fix: epoxy patches buy time on small holes; proper replacement is the real repair.
4. Broken Condensate Pump
When the air handler sits below the drain's exit path (garage installs, closets on slab), a small pump lifts the condensate out. If the pump dies, water accumulates until it overflows.
The tell: water rising in a pump reservoir that never kicks on, or a pump running constantly without moving water. The fix: pump repair or replacement, a quick professional job.
5. Refrigerant Leak
Low refrigerant drops the coil's pressure and temperature, freezing it just like starved airflow does, with the same melt-and-leak result. The refrigerant itself escapes through pinholes and worn connections.
The tell: weak cooling, hissing near the lines, and ice, together. The fix: professional leak detection and repair, because topping off without fixing the leak just rents you a few cool weeks. The signs of a refrigerant leak guide has the full symptom list.
6. Improper Installation
A unit that isn't level, or a drain line without steady downhill slope, leaves water with nowhere to go but sideways. This is the likely story when a system has leaked on and off since it was new.
The tell: chronic small leaks on a young system. For window units, check the tilt with a torpedo level: the outdoor side should sit slightly lower. For central systems, slope and trap corrections are an installer's fix.
Pan overflowing, or ice that keeps coming back? That's a same-day repair, not a watch-and-wait — every hour of leaking adds drywall, flooring, and mold risk to the bill. Sansone's South Florida team answers fast across the region: Broward (954) 800-2858, Palm Beach (561) 701-8274, St. Lucie (772) 879-5656. Upfront pricing before any work begins.
Can I Keep Running It While It Leaks?
No, and it's worth being blunt about why. Water pooling around electrical components is its own hazard, drywall and flooring damage compound by the hour, and in Florida humidity, mold gets started in wet material within a day or two.
If the cause is a frozen coil, running the system also forces the compressor (the most expensive component in the machine) to strain against ice. Shut it down, work the five steps, and get help if the water returns. A hot afternoon costs less than a ceiling.
Preventing the Next Leak
Flush the drain line seasonally. A cup of distilled vinegar down the line's access opening every month or two in cooling season keeps the algae from re-establishing. In our climate, that's the single highest-value habit on this list.
Change the filter monthly in summer. South Florida cooling season works filters harder than the box's "90 days" promise assumes. Our guide to how often to change your air filter has the honest schedule.
Add a float switch. This inexpensive device sits in the drain pan and shuts the system off automatically when water rises too high, converting a future flood into a no-cool call. If your system doesn't have one, ask for it at your next service visit; it's cheap insurance.
Book annual maintenance. A tune-up includes clearing the condensate system, checking the charge, and catching the rusting pan before it lets go. If you've noticed water dripping from a ceiling vent rather than the unit itself, that's its own diagnosis, covered in how to fix water dripping from an AC vent.
Contact Sansone for Leaking Water From Your AC in South Florida
Whether it's a drain line that needs clearing, a pan that's rusted through, or a freeze-up that keeps returning, Sansone's licensed technicians diagnose the cause and quote the fix upfront, with same-day availability across the region.
Call the team nearest you — Broward (954) 800-2858, Palm Beach (561) 701-8274, St. Lucie (772) 879-5656 — or book online today.
Frequently Asked Questions
Why is my AC leaking water inside the house?
Most often a clogged condensate drain line backing water up into the drip pan until it overflows. Other causes: a frozen evaporator coil melting off more water than the pan handles, a rusted pan, a failed condensate pump, low refrigerant, or an improperly sloped installation. The leak's timing and location point to which.
Can I still use my AC if it's leaking water?
Turn it off. Running a leaking AC adds water damage by the hour, risks mold within a day or two, and, if the coil is frozen, strains the compressor. Work the basics first: filter, thaw, drain line. If water returns when the system restarts, keep it off and schedule repair.
How do I unclog my AC drain line?
Attach a wet/dry vacuum to the condensate outlet outside, seal the connection with a rag or tape, and run it for one to two minutes to pull the clog through. Then pour a cup of distilled vinegar into the line's access opening near the air handler to kill remaining algae.
Why is my AC leaking only when it's turned off?
That pattern points to a frozen evaporator coil. While running, the ice stays frozen; after shutdown it melts, releasing more water than the pan and drain can carry. Replace the filter, let the system thaw fully, and if ice returns, have the airflow and refrigerant charge checked professionally.
Is water leaking from an AC dangerous?
The water itself isn't hazardous, but what it does is: it damages drywall and flooring, feeds mold growth within a day or two in Florida humidity, and pools near electrical components. A leak also signals the system needs attention, since several causes worsen the longer they run.
How do I stop my AC from leaking in the future?
Four habits: flush the drain line with vinegar regularly during cooling season, change the filter monthly in summer, have annual professional maintenance that clears the condensate system, and add a float switch that shuts the unit off before the pan can overflow. Together they prevent nearly every common leak.
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