Performed annual heating maintenance 20 yr split Goodman upflow system , upstairs closet. System is operational at this time. Not in the best shape. Has had some repairs done in the past. Newer hot surface ignitor. Cleaned up burners and flame sensors. Filter has just been changed. 16-25-1. Blower motor appears to have been replaced as well. Blower wheel starting to get dust on it. Furnace runs on LP. Gas line into system doesn’t have a drip leg, not to code. Burner compartment has burn mark in it, not sure where they came from. Burning well at this time. Checked seals on unit to plenum, tape is starting to separate in back left corner but doesn’t seem to be leaking air yet, we can keep an eye on it. Unit rattles a little bit, we will keep an eye on it. Electrical board looks ok, no burn marks or burnt wires at this time. System is operational at this time. Due to age and efficiency of system recommend looking into replacement options before failure.