Came out today for 1 system maintenance. Upon arrival started by checked heating sequence to verify proper heating sequence. All components are operating as designed safeties are operating properly at this time. Evap coil is clean but has rust forming on it. Ducts are a combination of flex metal and grey back and ducts need to be cleaned and some of the ducts are damaged recommend duct replacement. Outside unit is from 1998 and R22 recommend replacing system due to age and type of refrigerant. System is operating in heating and cooling at this time. Customer approved pan treatment and blow kit. Pan treatment and blow out kit