On arrival I spoke with Dan and he said the system had frozen over yesterday from the indoor coil to the outdoor compressor. Service diagnostic found that the system was low on refrigerant. I spoke with Dan and he chose to add refrigerant to the system. I added 2 pounds of refrigerant and performed a leak search. I was unable to find a leak at this time. I asked Dan to keep an eye on the system and give us a call if it happens again. The system is running at completion of service.