Arrived on site to perform maintenance on 8 year old Goodman furnace. As spoken over with homeowner on previous visit, this is a single stage system that is zoned off into 2 separate zones. Cycled both zones for heat. Verified proper heating sequence of operations. Temperature rise is normal. Tested all heating safety components. Wiped off blower assembly and heating compartment. Cleaned flame sensor. Ran system through 20 point inspection checklist. Indoor Blower wheel is clean. Indoor secondary motor control is within range. Condensation lines do not have any condensation safety switches in the event that the line would get clogged. Went over some indoor air purification and filtration as homeowner had brought it up on first visit that we came out here. Replaced 1 inch filters. Went over findings and recommendations with homeowner. Cycled system, system is operational upon departure.