Broken wheel roller on a PAC-121 portable air conditioner

Try viewing the owner's manual here for further instructions about the reservoir. Page 10 of Heat Controller Inc OWNER MANUAL Portable Air Conditioner PE...

OWNERS MANUAL for DELONHI
PAC W130
http://www.delonghi.com/Global/InstructionManuals/GB/GB-5751018800.pdf

I am also looking for an "upper Blower wheel' for my Whirlpool portable Air Conditioner and have not been able to find one. The model # is: ACP122GPW. I've looked all over town, even ordered one, and it was too small. I believe the part # is: 09040193. Can you help?

My DeLonghi PAC L90 Portable Air Conditioner does not blow out cold air,only has cool air

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.)

should have drain pan that has to drain or be emptied out.

sounds like a broken blower wheel.

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

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.