Performed maintenance on all three systems. Replaced all three filters two pieces 16 x 20 x 1 and one 16 x 25 x 1. Cleared and treated condensate drain lines and pumps with chlorinated tablets. Inspected electrical connections and components as well as refrigerant levels. Cleaned outdoor condensing coils. Also replaced defrost control board for upstairs system outdoor unit. After replacing defrost control board, technician tested system operations and unit is now operating properly.