Preformed fall service on up flow 80% furnace cleaned flame sensor checked amps on all motors inspected blower wheel and evaporator both where clean the system has a surge protector installed. Inspected dryer vent it looked good and sealed checked flashing g it was sealed and found no presence of water ran system through a cycle the system is operating correctly at this time. Customer changes filters regularly ðŸ˜ðŸ˜ did a return air calculation and it was good at 1,100 CFM on two and a half tons only requires 1,000 cfm