A few years ago a buddy of mine decided to upgrade the central heating and cooling component in his house. He lives in a warm area so his air conditioning runs almost continuously. He has to have a legitimately dependable component so he bought a top of the line model to have installed at his home; When the HVAC contractor brought the component to his home to start the installation process, he asked the contractor if the air conditioner came with an overflow kill switch. The HVAC worker just nodded, but he never got anything in writing about the air conditioning overflow kill switch. This was not good, because about one week later, he had a major leak in the up-to-date unit. There apparently wasn’t an overflow kill switch after all. The major leak that the heating and cooling component had led to him getting mold in his home. The HVAC contractor didn’t put in the switch after all. The HVAC company also refused to take any responsibility for the accident that had occurred, and my exhausting buddy ended up having to pay thousands of dollars in repairs for what the leak had caused. Then he also had to pay for service as well as maintenance on his brand new up-to-date central heating and cooling system, too! I suppose the moral of the story here is to consistently ask a ton of questions before working with any heating and cooling business, and always get everything in writing!