Performed AC diagnostic on 2010 Carrier condenser. Upon my maintenance Zachary it’s stated that about three years ago the system was re-charge in a sealant was added into the refrigeration cycle. Verified that indoor system is running and outdoor system is pumping. Found that the system was significantly low on refrigerant this is due to a leak somewhere within the evaporator coil, line set or condenser coil. Informed Zachary that it is vital that the leak is found to prevent any further refrigerant loss. Add it in approximately 5 pounds of refrigerant and a leak dye to help pinpoint where leakage is occurring. Advising that the repair for the leak is separate from these repairs today. After charging the system up there was a 16 degree split. Will be returning in approximately 1 month for leak dye search. System is fully operational upon departure.