The answer to 'heat pump making loud noise' is that there are several common causes, including worn bearings, compressor issues, and refrigerant leaks. The symptoms may include a grinding, screeching, or rattling noise coming from the outdoor unit. If the noise is persistent and getting louder, it's best to call a professional HVAC technician to diagnose and repair the issue.
Homeowners should avoid trying to fix the heat pump themselves, as improper repairs can lead to further damage or safety hazards. HVAC systems contain pressurized refrigerant and electrical components that require specialized training and tools to service safely. A qualified technician will be able to identify the root cause of the noise and recommend the appropriate repairs.