2013 comfort maker high efficiency natural gas furnace heating system tune-up, maintenance, cleaning, and safety inspection Run test all equipment in multi-stage heating, remove and flush drain trap assembly, resurface flame sensor and inspecting igniter, shop-vac all equipment, replace air filter and humidifier pad with supplies already on site. Test run humidifier and confirm controls on nest thermostat. Perform furnace combustion analysis and performance inspection at 93% EFF with 7.0% oxygen and 14 PPM co Internal house airstream inspection confirms 20.9% oxygen and zero PPM Co Basement system is clean safe and ready for winter Homeowner will set humidity on the nest thermostat when the time is right