The answer to 'replacement making noise' is that a noisy HVAC replacement unit can be caused by a few common issues. This could be due to improper installation, loose components, a problem with the fan or compressor, or even just normal wear and tear over time. Some symptoms include grinding, rattling, or high-pitched whining noises coming from the unit.
In many cases, the solution may be as simple as tightening bolts or replacing a faulty part. However, if the issue is more complex, it's best to call in a professional HVAC technician to diagnose and repair the problem. Attempting DIY repairs on an HVAC system can be dangerous and may even void the warranty, so it's generally recommended to have a qualified service tech handle any major repairs or replacements.