Upon my arrival I performed a 6 month checkup on 1 heat pump system. I flushed and treated the water removal system, washed the condenser coil using water, cleaned and treated the electrical cabinet with electrical insecticide, replaced the air filter then verified system safety and performance. I found the system is low on refrigerant due to a leak at the heat transfer media coil detected with electronic leak detector. I spoke with the customer about my concerns and presented repair options. HL1C was approved today and 10% down payment was collected.