Performed 2 system inspections. Upstairs system is a 2021 carrier system and the mainfloor is a 2014 Lennox system (outdoor unit) indoor is 2021 carrier system (for the indoor). I flushed the drain lines. I changed the air filters. I tested the heating and cooling systems and verified that there were no issues with the heating and cooling systems. No issues found at the time of service call. I emailed options for indoor air quality products and updated flood protection (recommendations only). There is a small section of flue pipe (mainfloor furnace) leaving the furnace that the homeowner may want to consider upgrading to double wall flue pipe; emailed estimate to upgrade it. Flue pipe on main floor system does have a heat shield separating it form the duct work.