Performed furnace clean and tune; inspected the exhaust and intake PVC ensuring all connections were secured, removed and cleaned the burners along with the flame sensor, cycled the system on and checked gas pressures, as well as performed a combustion test verifying no CO in the airstream. This system is currently operating normal and heating at 57 degrees at this time. Due to the amount of dust build up on the blower wheel I highly recommend upgrading to an electronic air cleaner to bring these levels of dust in the home down. Job complete