# SCENARIO GUIDE · AC DRAIN LINE LEAK

AC leaking water through the ceiling: what to do first

If your AC is leaking water through the ceiling, turn the system off at the thermostat, catch the water, and move belongings. A clogged condensate drain line is a common cause: an HVAC technician clears it, and a restoration company dries the ceiling and insulation so mold doesn't start (EPA: dry within 24-48 hours). In the Orlando area, call or text CFDR at 321-420-7274.

Updated Oct 2026

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Four steps while the water is still coming

1
Turn the AC off
Switch the system off at the thermostat. If water is near the air handler's wiring or the ceiling is wet around a light or fan, also turn off that breaker.
2
Catch the water and clear the area
Set out buckets, move furniture and electronics, and keep everyone out from under a ceiling that sags or bulges.
3
Photograph it
Photograph the stain, the drain pan or line, and the wet floor. Note the date and time you found it; your insurer will ask.
4
Get the line cleared and the ceiling dried
An HVAC technician clears or repairs the condensate line. A restoration company dries the ceiling and insulation, ideally within 24-48 hours.

Who fixes what after an AC leak

HVAC technician

Clears or repairs the condensate line, checks the float switch and drain pan, and reroutes a misrun line.

Restoration company

Finds the wet areas with a moisture meter, removes wet insulation and drywall that cannot be dried, and dries the cavity. CFDR matches you with one.

Your insurer

Decides what your policy covers. Report the loss early; ask what it needs from you.

Citizens policyholder? Call Citizens first (866-411-2742); with other insurers, ask about managed-repair rules before you sign a repair contract.

What the condensate drain line does

Your air conditioner pulls moisture out of the air. That water, called condensate, collects in a drain pan and leaves the house through a small PVC line (about the width of a finger) that ends outside or at a drain. In Florida the AC runs most of the year, so algae and sediment build up in that line. When it clogs, the water has nowhere to go and backs up into the pan, the attic or the ceiling.

The volume is larger than most people expect: on a typical Florida summer day a central air system can remove 5-20 gallons of water from the air, and in Central Florida it runs almost continuously from March through November. Because most air handlers sit in the attic, an overflow soaks the insulation first and then the ceiling drywall, and it often goes unnoticed until a stain appears, by which point the leak has been running for days or weeks and mold is usually already present.

What causes a condensate backup

Clogged drain line
Algae, mold and debris build up in the line over time. This is the number one cause.
Cracked or broken drain pan
The secondary pan under the air handler can crack, especially on older units.
Disconnected drain line
Vibration can shake a line loose, especially on attic-mounted units.
Frozen evaporator coil
When a coil freezes and then thaws, the meltwater can overwhelm the drain system.

Warning signs of a clogged line

Water pooling under or around the indoor unit
The line is backing up at the source. Turn the AC off.
Musty smell in rooms below the air handler
Moisture has been present for a while. Check the attic and ceiling, and dry anything wet within 24-48 hours.
Stains or sagging on a ceiling under the attic unit
Water has reached the drywall. Keep out from under a sagging section.
No dripping from the outdoor drain line on a hot day
The line may be starting to clog. Clean it before it overflows.
Slime or algae visible at the line opening or in the pan
Growth inside the line is the usual cause of a clog. Clean it now.

How to flush the line before it clogs

If the line is slow but not backing up into the house, you can clear it yourself. If water is already coming into the home, skip this and call an HVAC technician.

Turn the AC off at the thermostat and the breaker.
Find the cleanout tee on the PVC line near the indoor unit and the outdoor end of the line.
Hold a wet/dry vacuum hose against the outdoor end and run it for a minute or two to pull out the clog.
Pour about a cup of distilled white vinegar down the cleanout tee. Never mix it with bleach.
Check that water runs freely, then restore power. Repeat every month or two in the humid season.

Preventing the next backup

Flush the line with vinegar every month or two in the humid season (steps below).
Have the AC serviced annually; the technician checks the drain pan and line.
Ask for a float switch or condensate overflow sensor that shuts the system off when the pan fills.
Know where the secondary drain pan is and check it monthly.

A float switch or overflow sensor stops many of these leaks before they reach the ceiling; ask an HVAC technician about adding one.

Mold after an AC leak

The EPA says most mold will not grow if water-damaged areas and items are dried within 24-48 hours. Attic insulation holds water, so it is the first thing to check. Florida requires a licensed Mold Assessor (MRSA) to assess, and a licensed Mold Remediator (MRSR) to remove, mold growth larger than 10 square feet; the company that assesses a home generally may not remediate it within 12 months (ss. 468.8411, 468.8419). Look up any company's license at the state license search before work starts.

Common questions about AC condensate leaks

Why is my AC making my ceiling wet?+

Usually the condensate drain line is clogged, so the drain pan overflows or the line leaks. If the air handler is in the attic, the water soaks insulation first and then the drywall, so a ceiling stain can show up days after the leak began. Turn the AC off at the thermostat and the breaker, then have an HVAC technician clear the line.

What is the difference between the primary and secondary drain pan?+

The primary pan sits inside the air handler and drains through the main line. The secondary (auxiliary) pan sits under the unit as a backup, and its separate drain line usually ends above a window or door outside. Water dripping from that backup line means the primary line is clogged. Treat it as a warning and have the line cleared before the backup fails too.

How do I clear a clogged AC drain line myself?+

With the AC off, locate the outdoor end of the white PVC line, hold a wet/dry vacuum hose against it and run the vacuum for a minute or two to pull the clog out. Then pour a cup of distilled white vinegar down the cleanout tee inside. Never mix bleach and vinegar, because the mix releases toxic chlorine gas. If water still backs up, stop and call an HVAC technician.

How fast do I need to dry a ceiling after an AC leak?+

The EPA advises drying water-damaged areas and items within 24-48 hours to prevent mold growth. Wet attic insulation and drywall usually have to be removed, not dried in place. A restoration company measures moisture and dries the cavity; an HVAC technician fixes the cause.

How much water does a Florida AC produce?+

On a typical Florida summer day a central air system can pull 5-20 gallons of water out of the air, and in Central Florida the system runs almost continuously from March through November. All of it leaves through the condensate line, which is why a clog can soak an attic in a day.

Is AC condensate clean water?+

It starts as Category 1 (clean) water, but it becomes Category 2 as it sits in insulation and drywall. The sooner the ceiling is extracted and dried, the less likely mold becomes a second problem.

Does homeowners insurance cover AC water damage?+

It depends on your policy. Many forms cover sudden and accidental water discharge and exclude long-term seepage or leakage, so the cause and the date you discovered it matter. Photograph the damage, note the date, and ask your insurer what your policy says. Your insurer decides coverage; CFDR does not.

Who is CFDR?

Private Orlando restoration referral service, not FEMA. Call or text 321-420-7274 24/7 and Ryan Solberg matches you with a local restoration company. You pay CFDR nothing, and CFDR does not bill your insurer.

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