Upon my arrival, I performed a six month check up on one heat pump system. I flushed and treated the water removal system, wash the condenser coil, using water, clean and treated the electrical cabinet, then verified system safety and performance. I found that the system is low on refrigerant so I performed an electronic leak search on both the indoor and outdoor units. I found that there is a refrigerant leak on the indoor system when I spoke to the manufacturer, they had to get with the factory to find out if this heat transfer media coil is available or not. Once I obtain the information a part availability I will email options over to the customer For repair.