Check the filter before heating season and every month during sustained use. A filter that is too restrictive or left loaded can reduce airflow and add stress to the blower.
Keep vents and terminals clear
Do not close large numbers of supply registers. After snowfall, inspect exterior intake and exhaust terminals for blockage. Test carbon monoxide alarms regularly and replace them according to manufacturer dates.
Use the right professional
Accessible furnace cleaning addresses dust at the blower, cabinet and filter housing. Combustion, gas controls and venting safety require a licensed gas technician.