Furnace clean and tune. Cycled system. Checked heat exchanger, ok. No rust or corrosion found in chambers. Checked, removed, and cleaned burners and flame sensor. Both are in normal condition. Checked and adjusted gas pressures to maximize efficiency. Checked electrical connections and clamps. Tightened all. Ventor motor bearings are in normal condition. No leaks found. Checked filter. Filter is ok. Recommend replacement of filter before the beginning of the year. Preformed combustion test. Normal levels found. No CO found in airstream. System is operating normal at this time. Job complete.