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Window air conditioner · Repair Copilot

Window AC leaking water inside

A window AC leaking water inside the room is almost always a drainage problem — a clogged drain channel or a unit mounted level or tilted the wrong way, so condensate spills in instead of running out the back. Both are DIY fixes. Show SightLine the unit and how it sits in the window and a handyman persona walks you through getting the water going the right direction.

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Steps to fix window ac leaking water inside

  1. Unplug the unit before working on it.
  2. Check the tilt: a window AC should sit with the back slightly LOWER than the front so water drains outdoors — if it's level or tilted inward, water pools and leaks into the room.
  3. Adjust the mounting so it tips gently backward (a small shim under the front inside edge often does it), and confirm it's still secure in the window.
  4. Find the drain holes/channel at the back or bottom and clear any dirt, mold, leaves, or bug debris with a thin tool — a clogged drain is the other main cause.
  5. Wash the air filter too — a dirty filter can freeze the coil, and the melt overwhelms the drain and drips inside.
  6. If it's tilted correctly and the drain is clear but it still leaks inside, the condensate pan or a seal may be cracked — time to service or replace the unit.

Safety first: if a step calls for gas, a main water or sewer line, a service panel or main breaker, or a sealed refrigerant system, stop and call a licensed pro — Repair Copilot will tell you when you're there.