The answer to 'preventive maintenance making noise' is that there are several common causes for noises during HVAC preventive maintenance, including loose components, worn parts, and debris buildup. These symptoms may indicate issues that require professional attention.
Some common causes of noise during HVAC maintenance include loose fan blades, worn bearings, debris in the system, or issues with the compressor. These problems can lead to rattling, grinding, or other concerning sounds. While some minor issues may be DIY-friendly, more significant problems often require the expertise of a licensed HVAC technician to properly diagnose and resolve.