Performed heating maintenance on three 2 year old Lennox mini splits. Indoor Unit: Inspected filters and electrical connections. Tested operation of units, temperature rises were normal, inspected electrical connections. Blower wheels are balanced. Evaporator coils are clean. Outdoor Unit: Performed deep cleaning of condenser coil fins and external unit. Inspected electrical connections and electrical draw. Cleaned electrical compartment. Installed surge protection device on disconnect. Upon departure system is operational.