After spending over $500 on what WASNT wrong, I am now going to call a competitor to see if they can properly diagnose the problem with my AC. My AC went out upstairs and the first visit the techician checked everything and told me it was my thermostat and that I also needed 4 lbs of coolant. Five days later... it went out again. Same exact thing. They came back out and in just a matter of minutes said last time I had an "inside" problem, now I have an "outside" problem.. my compressor was bad. An extra $2500. Really? Oh, of course.. my compressor was working fine five days ago and "sometimes these things just happen". Well I obviously find that very hard to believe. I have two AC units, both 10 years old, and the other one is still working fine. BEWARE. While they are very responsive and very nice, I just wasted $500.