2017 Trane XT95 Fuenace. 16x25x1 air filter on schedule with Jack. Cleaned flame sensor. Flush out drain trap. Test run operation of heating from thermostat. Temperature rise of 53F with supply temp of 125F. Temperature rise specification of 30-60F. Blower motor and inducer motor running within spec. 2" Pvc flue in good condition with no sign of leaks. Jack brought up the concern of a metal on metal grinding noise. No noise was heard while on site for preventative maintenence inspection. If noise is heard again, it is recommended to try and take a video of the noise, and try to locate the place of origin to assist with diagnostics. System is currently operating with no suspected issues based on today's inspection and testing.