Check the filter monthly during peak heating and cooling seasons. Replace it according to actual loading and manufacturer guidance, not only the date printed on a generic reminder.
Every season
Keep supply and return registers open and unobstructed. Clear vegetation from outdoor equipment, check visible condensate drainage and listen for new sounds during startup.
Professional checks
Gas safety and combustion work belongs to a licensed technician. Source-removal and compatible HVAC cleaning address different parts of system care, so confirm scope when booking.