Arrived on site for heating maintenance on carrier two system 2017-2016 furnaces. Homeowner stated all was well with regard to normal unit operation to his knowledge. Proceeded with scheduled heating maintenance. 1. Visually inspected condenser coil for debris/ dirty. 2. Inspected condenser fan motor. 3. Inspected condenser fan blades. 4. Inspected/ cleaned wiring connections. 5. Tested for gas leaks 6. Tested functionality and cleaned flame sensor 7. Tested functionality and cleaned pressure switches and ports 8. Inspected / replaced return filter. 9. Inspected return plenum for debris/ dirty. 10. Inspected evaporator coil. 11. Tested functionality and visually inspected surface igniter 12. Checked blower amp draw. 13. Measured temperature differential from supply to return. 20 degrees measured. Noticed large amount of noise coming from inducer motor on downstairs unit. Made slight adjustment to induce her housing, and the noise went away altogether. This leads me to believe that t
