Completed a/c maintenance on 4 conventional adp air handlers with 4 trane condenser and two Mitsubishi ductless heads with one condenser. It is recommend to perform a duct cleaning on all units the duct work is very dusty. Also it is recommend to perform a deep cleaning on the blower wheel for the 1st floor system. During the maintenance found that the ductless units in the basement run for a few minutes then they stop working and start flashing error codes. The customer was not home at the time but we would need to return to further diagnose issues with tech support. Chemically cleaned all evaporator coil’s. Inspected blower compartment and primary drain pan. Treated and cleared all drain lines,traps and tested all condensate pumps. Brushed and cleaned all electrical cabinets and tighten and secured all electrical connections on both inside and outdoor units. Tested all safety switches all in working condition. Chemically cleaned all outdoor condenser’s checked operations and r