First year furnace clean and tune. Cycled system. Checked heat exchanger, ok. Checked, removed, and cleaned burners and flame sensor. Both ok. Igniter tested normal. Checked and adjusted gas pressures to maximize efficiency. Checked and tightened electrical connections and clamps. Cleared drain line. Preformed combustion test and found normal levels in exhaust. No CO found in airstream. System operating normal at this time. Job complete