Arrived at customers residence and was greeted by customers friend and was led to the thermostat and it functioning properly put it in heat mode and went basement and it running at present. Sent endoscope camera into the burn tubes of the heat exchanger and found the 2 out of the four tubes have seams that are failing,at this time have couple of pictures to confirm findings also found that flame sensor is dirty causing furnace to shut off during the lighting process at this time. Refrigerant lines are tight and neat and Arma flex is intact and without any visible defects at this time . Inspected washable. Filter and it is extremely,matted and dirty at this time. Inspected blower motor and wheel and both are extremely dirty at this time. Entire cabinet,is very dirty with dust dirt and debris. Inspected evaporator coil coil and it is extremely covered in dirt and debris at this time. Inspected condensate pump and it is functioning properly at this time. Inducer draft motor is fu