Arrived to remedy a communication error. Upon inspection of the system found that the fault code has disappeared and the system seems to be communicating. Checked the outside unit for loose or damaged connections. Checked the furnace for loose or damaged connections. Found that a wire that connects to the furnace control board was very loose and when touched became completely disconnected. Fixed this connection and made sure all other wired connections are secure. Homeowner wished to join the maintenance family and have a furnace tune up performed. Set up for combustion analysis temperature split and static pressure tests. Found that the system is operating with excessive static pressure. Verified operation of all mechanical and electronic components of the furnace. Checked blower for cleanliness and to see if there is any play in the bearings. Found that the fan is heavily coated in dust debris. Checked the ductwork to determine the cause of the debris. Found that the ductwork has exc