Client called to have furnace serviced. Tech went out furnace is a mid efficient carrier from 2008. No current issues. Tech tested the heating system: checked gas pressure, temperature, exhaust fan amperage test, blower motor amperage test, flame rectification sensor test, exhaust fan vacuum test, ignition system tests, pull and inspected both blower motor assembly and their capacitors. Inspected both heat exchangers for any deficiencies. Tech noticed the ducts are getting dirty. Tech informed client. Client thanked us for coming out. System is working well at this time.