Arrived to do a performance maintenance. Set up for combustion analysis temperature split and static pressure tests. Found that the system is operating with failing static pressure. Reached out to a field supervisor to finish the diagnosis on the systems 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 excessive debris built up on the blower wheel. Checked systems heat exchanger to ensure proper venting of flue gas. Spoke with homeowner about the system. Furnace is operational at this time.