Most AC parts like the evaporator and the condenser are sealed. Therefore, DIY projects are usually not recommended, a professional service person should be called for almost any maintenance other than a routine cleaning. Central air conditioners should be professionally inspected and adjusted before the beginning of every cooling season, or here in Florida every 6-9 months. However, don't let your maintenance end with this annual checkup. While there aren't many repairs you can make yourself, there are specific maintenance procedures you can follow to keep your system operating at peak efficiency.