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. 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 bearings for the fan are making excessive noise. Checked systems heat exchanger to ensure proper venting of flue gas. Found debris that has fallen off the evaporator coil. Performed an electronic gas leak search. Furnace is operational at this time.