Window AC unit leaking water

Symptoms

• Water dripping inside the room from the front of the unit
• Water pooling on the windowsill or floor indoors
• Water dripping outside is often normal and not a problem

Likely causes

• CommonUnit not tilted slightly toward the outsideWindow units need a slight backward tilt so condensate drains outside instead of into the room.
• CommonClogged internal drain hole or panDust and debris can clog the small drain opening designed to let water escape outside.
• PossibleDirty filter causing excess condensationReduced airflow can cause more moisture to collect than the unit's drain path can handle.
• PossibleFrozen coil that has thawed and produced excess waterMore water than usual right after a freeze-thaw cycle can briefly overwhelm the drain path.

What to do

1. Check that the unit is tilted slightly downward toward the outside, typically about a quarter to half inch; adjust the mounting brackets if needed.
2. Turn off and unplug the unit, then remove the front cover per the manual to check for a clogged drain hole or pan.
3. Clean out any visible dust or debris blocking the drain path.
4. Clean or replace the filter to reduce excess condensation buildup.
5. If the coil recently had ice on it, allow full thawing time before judging whether leaking continues.
6. Reassemble, reinstall with the correct tilt, and monitor for continued leaking during the next cooling cycle.

Tools and parts

• Screwdriver

When to call a pro

If leaking continues after correcting tilt and clearing the drain, replacement is often more practical than repair for a window unit.

Safety