Performed duct cleaning and sanitizing on a Furnace unit for the entire house system. Remove all floor grilles and vacuum clean. Clean and polish floor boots. Clean with duct cleaning equipment. Cut access opening in main trunk line of supply and return duct. Clean thoroughly with duct cleaning equipment. Secure openings with patch plate, screws and aluminum tape. Remove old filter. Clean return box and evaporator coil. Replace custom filter. Ran fan and sanitize @ return. Customer was advised to put thermostat back after 5-10 minutes from fan On to fan Auto for normal operation. System is operating normally. View visual findings from this job here - https://visionshare.xoi.io/?id=XA-A243-B0711789B98D47A59E9B1909B40E8CED