hello i have a duo therm a/c last year it blew cold but leaked water. earlier this year it seemed fine blew cold but didnt leak water well today i stated it up and its blowing but not cold...just blowing air. what could the problem be? its an older model duo therm brisk air the unit is so old that all the numbers is faded the only thing i found was on the back of the "radiator?" it said L843174 but i know thats not the model number....i found the installation instructions but I can only tell you its a 559 series, 579 series OR a 557 series and heres a bunch of models it COULD be i cant find anything on it its self because everything is faded and worn off. the thermostat is on the ceiling sort of like built into the system if that makes sense. any help would be appreciated!