Opie's One Hour Heating and Air installed my system about nine years ago, and they come out every year to service the system and make sure things are running fine. They used to come twice a year, but we don't use our air conditioner as much so I just have them come out once every fall for maintenance. The tech who came out was very open and willing to discuss and answer any questions I might have. He pointed out things, and along with replacing my filter and providing maintenance, he found a part that was leaking, which he promptly replaced. He was fine. He was personable, kept everything clean, and I had no problems.