An AC leaking water inside usually has a clogged condensate drain line, an overflowing or rusted drain pan, a disconnected drain fitting, or a frozen evaporator coil. Turn the system off, check the drain pan and line, and call an HVAC technician. Dry any wet floors, walls or ceilings quickly, because slow AC leaks are a common cause of hidden mold.
Why your AC makes water at all
Your air conditioner cools by passing warm indoor air over a cold evaporator coil. Moisture in the air condenses on the coil, drips into a drain pan and flows out through a condensate line, usually PVC pipe running outside or to a drain. In Miami-Dade's humid climate, that can be a lot of water every day during summer. When anything blocks that path, water backs up.
Five common causes
- Clogged condensate line. Algae and sludge grow inside the line in warm weather. This is the most common cause.
- Rusted or cracked drain pan. Older metal pans corrode through, so water leaks even when the line is clear.
- Disconnected or broken drain fitting. Fittings can separate, especially after other work in the closet or attic.
- Frozen evaporator coil. A dirty filter, blocked return or low refrigerant can freeze the coil; when it thaws, the pan overflows.
- Failed float switch. This safety switch should shut the system off when the pan fills. If it's missing or stuck, overflow continues.
What to do right now
- Turn the AC off at the thermostat.
- Soak up water and protect the floor and anything stored in the closet.
- Look at the drain pan: full means a clog; rusty or cracked means it needs replacing.
- Check and replace the air filter if it's dirty.
- Call an HVAC technician to clear the line or repair the unit.
Checking for water damage
Water from an AC closet often spreads under baseboards and flooring in the hallway, and water from an attic unit soaks insulation and drywall above the ceiling. Signs to look for: stains, bubbling paint, swollen baseboards, soft drywall and a musty smell. A moisture meter shows how far the water went. If the area stays damp, mold can start. See AC leak water damage and ceiling water damage.
Prevention tips for South Florida
| Task | How often |
|---|---|
| Replace the air filter | As recommended for your filter type, often every 1–3 months |
| Have the condensate line flushed | During routine HVAC maintenance |
| Look at the drain pan and float switch | A few times a year, especially before summer |
| Check the outdoor drain outlet is dripping | Monthly when the AC runs a lot |
| Install a leak sensor in the AC closet | Once |
If an AC leak has already wet floors, walls or ceilings, call (786) 732-2700 for drying.
Frequently asked questions
Why is water dripping from my AC vent?
Water from a supply vent often means condensation on cold ducts or vents in humid air, or a leak from an attic air handler above. Have an HVAC technician check duct insulation and the unit.
How do I unclog my AC drain line?
Many lines have a cleanout or access tee where a technician flushes the line or uses a wet/dry vac at the outdoor end. If you're not comfortable doing it, call an HVAC technician.
Can a leaking AC cause mold?
Yes. Repeated leaks keep closet floors, baseboards and drywall damp, which is ideal for mold in South Florida's humidity.
Is a little water around the AC normal?
Water should drain away through the condensate line, not collect around the unit. Any standing water inside means something needs attention.
Who should I call for an AC leak?
An HVAC technician fixes the unit and drain line. If floors, walls or ceilings got wet, a water damage restoration team handles drying.
More water damage guides
- Water Damage in Your Home: What to Do in the First 24 Hours
- Water Damage Categories and Classes, Explained Simply
- Filing a Water Damage Insurance Claim in Florida: A Homeowner's Guide
- Hurricane Season Water Damage Prep for Tamiami Homes
- How Long Does Water Damage Restoration Take?
Related services: AC Leak Water Damage · Ceiling & Roof Leak Water Damage · Mold Remediation After Water Damage · Water damage restoration in Tamiami