Why Is My AC Unit Leaking Water Inside the House?

An indoor AC unit leaking water usually means a clogged condensate drain line or a frozen evaporator coil. Clearing the blockage stops the leak.

Category:HVAC

Difficulty:Moderate

Time:1 hour

Success:50%

Updated:May 29, 2026

quick_referenceQuick Answer

For Why Is My AC Unit Leaking Water Inside the House?, start with "Locate the condensate drain line": Find the PVC pipe coming from your indoor air handler. It usually exits near the outdoor unit or into a floor drain. Stop DIY if the drain pan is rusted through or cracked. This is listed as a moderate recovery and usually takes about 1 hour.

verifiedGuide Snapshot

Repair areaHVAC

Estimated time1 hour

DifficultyModerate

Stop conditions3

Last updated May 29, 2026. Review the stop conditions before continuing.

account_treeRecovery State

DeviceAc Unit

Current stateWater Leak

Specific stateIndoor Leak

Failed stepCondensate Drain Clog

Likely failure typeBlocked Path

DIY boundaryDIY recovery first

paymentsCost decision

help1. Understand the Problem

Your air conditioner produces condensation as it cools. Normally, this water drains outside through a plastic line. If that line gets clogged with algae or debris, water backs up and overflows the drain pan, leaking into your home.

build_circle2. Try This First

Best First Step

Locate the condensate drain line

Find the PVC pipe coming from your indoor air handler. It usually exits near the outdoor unit or into a floor drain.

visibility3. Visual Guidance

See what's happening and how to try the first recovery step.

Clear the drain line with a wet/dry vacuumSeal the vacuum hose to the drain line end. Run the vacuum for 2-3 minutes to suction out the clog.

Flush the line with distilled vinegarPour 1 cup of distilled vinegar into the drain line access port. Let it sit for 30 minutes, then flush with water.

Check the drain pan for standing waterLook under the air handler for the drain pan. If water is present, the clog is cleared and the pan will drain.

Restart the AC and monitorTurn the AC back on. Watch the drain line for steady water flow outside. Check for leaks over the next hour.

autorenew4. If That Doesn't Work

Try the next recovery options.

Turn off the AC and let the coil thawIf the coil is frozen, turn off the system for a few hours. Ice melting can clear minor clogs and stop the leak temporarily.

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Pour vinegar down the condensate lineMix 50/50 vinegar and water and pour it into the condensate drain opening to kill algae growth.

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