I have used Hi-Tech Air Conditioning for over 10 years and I had always been very pleased. They installed my air conditioning unit and service it regularly. On their most recent visit, however, it went horribly. The technician came late and that was frustrating because I needed to leave the house. My son showed him the unit and how to take it apart to clean it correctly. He wanted to perform the service his own way, but I had been told by many technicians before to never do what he was doing. He also informed me about all these things that needed to be done. He was very critical about how the unit was installed incorrectly even though it was Hi-Tech that did the installation in the first place. He sent me an estimate for all the work that needed to be done and it cost $750. Never before had any technician ever told me that and it was like he was trying to push to sell me things that I did not need. The only thing that I know for sure that he did was change the filter. Other than that, I do not even think that he checked the coolant level. The unit is working fine, but I am thinking about using another company to do the routine maintenance services.