Maintenance and service must be performed by a qualified installer or service agency. At the beginning of each cooling season, the system should be checked as follows:
NOTE ‐ If insufficient cooling occurs, the unit should be gauged and refrigerant charge should be checked.
Cleaning of the outdoor unit's coil should be performed by a trained service technician. Contact your dealer and set up a schedule (preferably twice a year, but at least once a year) to inspect and service your outdoor unit. The following maintenance may be performed by the homeowner.
The outdoor unit must be properly maintained to ensure its proper operation.
In order to ensure peak performance, your system must be properly maintained. Clogged filters and blocked airflow prevent your unit from operating at its most efficient level.
Source: MaintainX (Community Member)