Arrived to do a performance maintenance. Set up for combustion analysis temperature split and static pressure tests. Tuned the gas valve to a safe and efficient burn. Adjusted fan speeds to allow a better temperature split and lower 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 that the fan for heating and cooling is collecting dust. Checked systems heat exchanger to ensure proper venting of flue gas. Found that the evaporator pan is deformed and can leak condensation into the furnace. Performed an electronic gas leak search. Furnace is operational at this time.