Today I arrived on site to address the reported issue with the HeatPump condenser. Service Actions: Identified the HeatPump condenser on the left side of the house heating system as the source of the noise complaint. Discovered low pressure within the system. Charged the system with 3 lbs of R410A refrigerant. Verified the system is now operating correctly. Upon arriving at the property, the client was not on the property. The customer left the door unlocked to give us access to verify the system. I proceeded to run the system. I didn't find any noise at the time of the verification of the unit. I noticed that the condenser coil was freezing, which indicated signs of low system pressure. I checked the system pressures, Pressures out of ranges. Contact Bosch tech support to check the operation and temperatures of the system. Tech support confirmed and recommended that I add refrigerant to the system taking into account the length of the system line set. In total I added 3 Lbs