Performed preventative maintenance for air conditioning system. Did not replace Merv 16 (20x25x5) filter due to replacing it in January 2021 and the filter is good for a year. Check the filter anyway to make sure it was in good shape. Inspected all the electrical components. Confirmed proper high and low voltages. Made sure the primary and secondary drains were clear of any blockage. Tested the temperature split between the supply and return. System is operating with a 19° differential on a 66° day. Tested the amp draw from the compressor, blower and fan motor. All are operating within the manufacturer spec. System is operating at maximum performance at this time.