Inspect the homeowner-maintenance parts
Switch the system off and check the removable filter according to the manufacturer instructions. Note whether it is becoming dusty faster than usual.
Compare four simple signals
Check startup odour, airflow, visible buildup and any sign of water around the indoor head. Compare them with the system's normal operation.
Choose the right level of work
A normal filter clean may be enough. A light maintenance visit, deeper clean or technician inspection may be appropriate when the condition or operating signs have changed.
The practical takeaway
Use six months as a reminder to inspect, then let the condition of the system determine the service required.