Ultimate Cooling Tune-Up: cleaned coils, brushed and cleaned traps, added pan treatment tablets to pan. tested and checked all controls, wiring connections. tested temperatures, checked filters. checked refrigerant temperature and pressures, tested static duct pressure. tested blower operation, tested cooling operation to ensure working within manufacturer specifications Found first floor Maytag low on 410a. System is 18 years old and possibly has a leak. Was told not to add refrigerant and to set up a quote for replacement. Mitsubishi and Bosch systems are working well