Last year I bought an LG Electronics 12,000 BTU portable air conditioner. It worked quite well last year. It cools the house well this year, too. But…
Three days after the warranty expired, it’s dumping water on the floor. When I drain the reservoir, there’s only 70 or 75 ml in it. Much more water is leaking out of the bottom of the machine. I put some 2x6s in the bottom of a storage container and put the a/c on top of them so we can continue to use it.
Water condenses out of the air onto the evaporator coil. In normal operation that water drips down and is collected somehow and routed to the collection tank.
Presumably something is blocking that drainage pathway. The condensing water can wash off any dust that might have built up over the year and block the drain path, whether that is a tube or not. This allows the water to start to build up somewhere it wasn’t designed to build up and ultimately overflow where you don;t want the water to go.
You may be seeing the “drop which broke the dam” - water had been pooling somewhere it wasn’t supposed to, creating a small pond.
Eventually, that “pond” found a route to free air - and the route wasn’t the one the designers had in mind.
Open it up, find the coil, and start looking for its designed path to the reservoir.
Then find the route is has found.
I didn’t open it up, but I did put a hose on the reservoir drain and into a gallon Gatorade bottle. So far the bottom of the tub is dry and the water is going into the jug. So far.