I have 2 units- one upstairs and one downstairs- The upstairs is blowing- I feel the air blowing- the thingamabob outside (can't think of the name) is operating, but no cold air. I did notice that there's no water being pumped out. I hear its the compressor, but hopefully it's something else. Is there a few other checks I can do before I call the rapis- I mean the HVAC guy? Thanks!