Ive installed Goodman for years, formally Janitrol. Trane, Goodman, or any installer will not guarantee your new system will not fail. If you are absent from home, you need to still check on your house for water leaks, theft, vandalism, fire, etc. Having a contractor available for problems is beneficial for you, especially if warranted, but home inspection is required of out of home occupants. Someone or thing has to alert to a problem, or do you expect the contractor to have a crystal ball?