Nest thermostat in home is not turning on the outdoor unit as it should. Inspection of both systems and finding that the outdoor unit did not have any refrigerant in it even though the levels should have been fine based on last inspection/maintenance date. While inspecting the indoor unit, a leak was found in one of the refrigerant pipe connections in the indoor unit. Notified the customer of the problem found and repaired the leak and charged the system to the proper levels. Ensure that after the repair, Nest was able to turn the outdoor unit on with no issues.