Knowing little about central air conditioning, I relied on Angie's List recommendations to choose a knowledgeable company when our ten-year-old upstairs A/C unit was failing. Unfortunately, in this case, past performance does not seem to have been a good indicator of future performance. The installer spent all day removing the old equipment from outside and in the attic, and replaced everything including the slab. He did not install the Trane unit that the salesman referenced, but instead put in a Carrier; frankly, I don't know the difference. After installation, everything seemed fine at first. The unit is certainly quieter. The first problem was that the work failed the building inspection, with two defects. Acosta did not follow up when they received the inspection notice, as we thought they should. Basically, they ignored us until we insisted that they remedy the installation work. The second problem was that the system failed after only a couple of weeks. It would come on and start blowing cool air, and then cycle back off almost immediately. Apparently, Acosta does not do repairs on the weekend, so we had to wait until Monday. The repairman, who was not the installer, said that the condensation drain was completely clogged. The installer had said that we should pour bleach in that line every couple of months, something we had never had to do in ten years with the previous system. Wouldn't you think that the installer would check that the drain line was clear? It should not have clogged up in two weeks. We also insisted that the repairman also fix the problems that caused the inspection failure. The repairman insisted on being paid $169 for his work. We followed up later with a company representative, who agreed to refund that charge. However, it took many weeks and several phone calls to finally get a check. We have not yet had the second building inspection (this requires that you take at least a half day off from work). So, this has become a two-month hassle involving us having to miss work three times. We have received no documents from the company -- no manual, no written warranty, nothing. I think that we should have received a written warranty. I said that I would use this company again, with some hesitation. I think that it is best to have future repairs done by the same company that did the installation. And I am willing to give them the benefit of the doubt, based on their past reports of good results. But I will certainly check Angie's List again at that time, to see if we are just an exceptional case, or whether the firm's performance has fallen below par for other customers.