Last summer they came out and said I should get a new unit but that they could clean the coil for a four digit figure. This summer they told me that I needed 3parts replaced in the condensing unit. for 1/4 of their estimate I replaced all parts and it made no difference in the indoor temperature. So I cleaned the coil that the recommended last year and that made no difference either. They are prompt and professional I just don't think they have the diagnosis thing down.