Strongly advise anyone to do so who hasn't had their HVAC system serviced for the summer season. Particularly the condensate drain, and particularly if the blower/coil resides in an attic.
I lost track of the time, it has been 4 years since mine leaked through the ceiling because someone had stepped on the edge of the galvanized overflow pan which bent it askew -- the blower/coil and return/outflow plenums block access through the attic, must crawl over the unit to get to the other side.
Made a mental note to check it, hadn't yet done so and this morning noticed dripping from the overflow outlet outside the house ... which serves as a visual indicator that the primary drain is clogged. Leastwise I had reasonably straightened the pan at the last leak so it now didn't run over.