Performed diagnostic on mini split system with 2 power heads. Found that the drain line for the leaking powerhead was caused by rats chewing thru the line before it connects to the pvc. The unit is on an interior wall. They have cut small access next to unit. Other access side of house roof next to outdoor unit. To fix problem would need to disconnect the unit from wall and remove and replace bad drain line. Then recommend running new pvc drain line to exterior to get proper slope in line. Then also at same time recommend cleaning washable filters at each powerhead. And washing the rooftop outside unit down. Cleaning the coils will help with Efficiency.