Performed preventative maintenance on 2 furnaces for customer. Customer is taking care of filters. Inspected ductwork, blower assemblies, electrical components, heat exchangers, burners, flame sensors, ignitors, gas valves, inducer motors and overall condition of all equipment. Inducer motor on older Trane unit is at max amps and is starting to make noise. Discussed with customer about possible repair needed. He wants to wait and just replace the unit when it goes out. Cleaned flame sensor and brushed dust off the burners and components. Checked operation, wiring, capacitor, amps, temperature rise and gas pressure of furnace. Systems are heating properly within manufactured specifications at this time.