Arrived to do a performance maintenance. 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 for heating and cooling is heavily coated in dust debris. Checked systems heat exchanger to ensure proper venting of flue gas. Furnace is operational at this time.