Performed A/C tune-up on a Carrier & American Standard heat pump system. Checked the electrical, mechanical and performance systems of the units. Cleared, cleaned, flushed and treated the drain lines. Cleaned the exterior of the air handlers and washed both outdoor coils. All filters were replaced recently and are clean. The evaporator coil for the guest bedroom system is very rusted but still operational. No other major issues were found. Both systems are working at this time.