Window AC Leaking Water Inside the House — Fixes
A window air conditioner is supposed to drain condensation out the back, not drip onto your floor. When it leaks inside, the cause is almost always how it's tilted or a blocked drain path — both easy fixes.
1. Check the Tilt
A window AC should sit dead level side-to-side and tilt very slightly DOWNWARD toward the outside (about a quarter inch) so condensation drains out the back. If it's tilted back toward the room (or perfectly flat), water pools inside and drips in. Adjust the unit or its support bracket so the rear sits slightly lower than the front.
2. Clear the Drain Hole / Channel
The drain hole or channel at the bottom-rear can clog with dirt, algae, and debris, so condensation backs up and overflows inside. Clear it with a pipe cleaner or compressed air. Some units have a drain plug — make sure it's positioned correctly for your install.
3. Clean a Frozen/Dirty Coil
A dirty filter or coils can cause the coil to ice up; when it melts, the volume of water overwhelms the drain and leaks inside. Clean the filter and coils, and don't run the AC when it's too cold out.
4. Check the Drain Pan
A cracked or rusted-through internal drain pan leaks water before it reaches the drain. Less common, but worth checking if tilt and drainage are correct.
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FAQ
Usually the unit is tilted back toward the room (it should tilt slightly down toward outside), or the drain hole is clogged so condensation backs up. Level it with a slight outward tilt and clear the drain.
Yes — slightly downward toward the outside (about a quarter inch) so condensation drains out the back instead of pooling inside.
Always unplug an appliance and shut off its water supply before servicing. This guide is informational and not a substitute for a qualified technician.