Perform a systems home care maintenance, tested all electrical components, flushed drain line, tested thermostat, Tested both system on cool and heat, checked pressures and refrigerant. System is working properly at this time, however, customer mentioned last visit tech had install IAQ product to eliminate the musty smell in the house but that the smell came back. When looking through system found that condensate drain line was completely clogged with mud, likely from the prior clean performed in the last visit, this could highly spread a musty smell throughout the house, then proceeded to replace condensate line and perform another evaporator coil clean. Also found duct work completely pack with hair a dust which it will also contribute with the musty smell coming back. Highly recommend to costumer to perform a duct cleaning. Costumer proceeded with recommendation and duct cleaning will be schedule by office. Thank you for choosing TE Certified,