Water where it shouldn’t be is alarming, but the cause is very often mechanical rather than a genuine fault.
Check the tank first, on tank-based units
Some portable ACs collect condensate in a removable tank rather than draining continuously. A full tank that isn’t emptied on schedule is the single most common cause of visible water — check and empty it before assuming anything else is wrong.
Drainage-free systems have a stated humidity ceiling
Dreo states the AC318S evaporates condensate automatically up to 90% relative humidity. Above that — genuinely rare indoors, but possible after heavy rain with windows open — the system may not keep up, and water can accumulate.
Check the unit is actually level
A portable AC tilted even slightly can prevent proper drainage or internal condensate routing, causing water to pool somewhere it shouldn’t. Confirm the unit is sitting level on a flat surface.
A blocked or kinked drain hose, on units that have one
If your model supports continuous drainage via a hose, check that hose isn’t kinked, blocked, or running uphill at any point — condensate needs a clear, generally downhill path to actually drain.
What we would not do
Assume any water is a sign of a failed compressor or refrigerant leak. In the overwhelming majority of cases across this family, it traces back to a tank, a level issue, or a blocked drain — all things a reader can check themselves before calling for service.
The questions that keep coming up
Is a drainage-free unit supposed to leak at all?
No, under normal operation — units like the Dreo AC318S describe automatic evaporation working up to a stated humidity ceiling. Above that ceiling, or if the internal pump or sensor system fails, water can accumulate. Check the manufacturer's stated humidity limit for your model.
Last reviewed 24 August 2026