After a dusty event
After sanding, building work or a period of open windows, inspect the accessible filter. Follow the manufacturer guidance for cleaning it and allow it to dry fully before reinstalling it.
After bringing home a pet
Pet hair and normal household dust are practical reasons to check the filter more often. The question is not whether every home has a problem; it is whether the filter and airflow look different from normal.
When the filter is not the answer
If the filter is clean but airflow remains weak, an odour returns or internal buildup is visible, take a photo and arrange a professional assessment of the accessible indoor components.
The practical takeaway
Household changes create a good maintenance prompt. Start with the filter, then use the condition of the system to decide the next step.