My Delonghi Pinguino PAC CT90 air conditioning unit seems to be dripping water from the bottom rear of the unit where there is a small opening that appears to either need a tube in it or a plug... Is there supposed to be a tube or plug? Or...how do I stop it from dripping water onto my carpet?? This is a floor-standing unit with the air intake/output (big) tube placed into a slight opening of my window. Your assistance would be greatly appreciated!!!!