Technician arrived to perform a yearly friends and family club furnace maintenance on a 2017 Lennox furnace. Technician adjusted gas pressure, checked amps, checked static pressure, checked temperature differential, cleaned flame sensor, changed filters and insured proper operation. Technician noticed bacterial growth on the condensate lines and dirt in the ductwork and built options on getting it cleaned and sanitized. Recommendations have been emailed to the customer for further review. System is heating properly at this time.