Condensate piping also known as a drain line is extremely important, not only to the unit but also your home. Wall-mounted units require a condensate drain line. It is important that you determine where the condensate drain line will go BEFORE installing the indoor unit. The condensate drain line typically requires a downward slope in the range of ¼ inch per foot, without any crimps in the line. One frequent source of callbacks is condensate (water) leakage. Water running down your wall can be an indication of an improperly installed drain line and/or your unit needing maintenance performed with the drain line blown out. It is also recommended that the condensate line be insulated due to sweating in the cooling season.