Arrived on site to perform fall tune up on a 2021 AcPro unit. Home was built in the 50s but found unit to have been replaced. Home only has heater. Cycled unit and was operational. Found filter be replaced. Blower assembly is good. Motor is good and in range. Inducer motor is good and in range. Flame sensor is good. Igniter is good. All safety switches are operational. Inspected attic and found all original metal ducts with a lot of leaks on connections. Insulation is coming off. And ducting are just small due to not a big home. Advised alot of rat poop in attic. Found asbestos B-vent for heater and water heater due to it being original from age. No protection on unit. Found gas flex line is going to unit to gas valve no sediment trap. Advised may be a safety concerns with inspection. Cycled unit and went over all findings with selling agent and she stated she would talk it over with new owner of home. Cycled system and unit is operational upon departure.