The answer to 'humidifier making noise' is that a noisy humidifier is often caused by mineral buildup, a worn-out fan, or an issue with the water supply. Common symptoms include loud rattling, buzzing, or whistling sounds coming from the unit. To troubleshoot, first check for any mineral deposits or scale buildup, which can cause the fan to vibrate and make noise. You may need to clean or descale the humidifier. If the fan itself is worn out, it will likely need to be replaced by a professional HVAC technician.
In some cases, the noise could be due to issues with the water supply, such as low water pressure or a clogged water line. Try adjusting the water flow or cleaning the water line. If the noise persists or you're unsure of the cause, it's best to call in an HVAC expert to diagnose and repair the issue.