Furnace clean and tune. Cycled system. Checked heat exchanger, found it very rusted and damaged. Several areas of deep rust and etching. Found igniter weak, but tested normal. Checked and cleaned burners and flame sensor. Found ventor noisy and bearings are worn. Found a large amount of water in burner compartment. Found transition assembly cracked. Also, rust found in blower compartment. Found no CO in airstream. Above average levels of XS air found in exhaust, indicating possible clogged secondary heat exchanger. Average life is this unit is 14 years. This system is very damaged and worn. Failure is expected. Due to age, condition, and cost to repair issues, second opinion is recommended. Checked aprilaire unit and found that the control is bad, not responding and now power out of control. Job complete.