Comfort-Aire PAC-121 leaking water all over the floor, water not going in drainage container

SOURCE: Comfort Aire PAC-121 problem

E4 shows up on the screen on my PAC-121 when the water reservoir on the right-hand-side is not pushed in all the way. If it is in all the way the switch that it engages may be bad or out of place.

SOURCE: poison

We searched the internet till we found something that put us at ease. still not 100% but at least 75%-90%.

SOURCE: I have a comfort aire

I have the same model, though several years old, and on mine E4 simply means the reservoir is full. Try emptying the reservoir tank and then turning the power on again. If the drain hose outlet isn't angled down, the water drains into the tank, which will need to be emptied regularly. (For constant use, may need to be emptied several times a day.)