The answer to 'furnace making noise' is that there can be several common causes, including worn bearings, a loose blower wheel, or issues with the motor or compressor. Symptoms may include grinding, squealing, or rattling noises coming from the furnace.
In many cases, these issues can be diagnosed and repaired by a skilled HVAC technician. However, some minor noises may be fixable through DIY maintenance, such as lubricating moving parts or tightening loose components. If the noises persist or worsen, it's best to call in a professional to properly inspect and repair the furnace to ensure safe and efficient operation.