03APR2023 Jason B Arrived for summer tune up, spoke with homeowners about the systems performance. It’s working great, however we still have that smell. Inspected air handler coil, plenum and ductwork. Cycled equipment in cooling, washed condenser coils, verified all components, pressures and amps are within manufacture tolerance. Inspected ductwork with Kianoosh for causes of the smell. Found all taps without dampers and 1 tap on the top of the plenum. We believe the lack of pressure on the plenum is causing growth. Spoke with homeowners about the plenum we decided to get it replaced. Office will contact you tomorrow for scheduling. System is running properly at this time. Plenum needs to be replaced with 4 ft plenum, 1-12”, 4-10”, 1-8”, 2-6”, 1-4” start collars with dampers and 90s.