The answer to 'why is my humidifier' is that there are several common causes for a humidifier not working properly. This could be due to mineral buildup, a malfunctioning humidifier component, or issues with the water supply. Symptoms may include decreased humidity output, strange noises, or the humidifier not turning on at all.
Some simple troubleshooting steps you can try at home include cleaning the humidifier, checking for any blockages, and ensuring the water supply is working correctly. However, for more complex issues or if you're not comfortable performing maintenance, it's best to call in a professional HVAC technician to diagnose and repair the problem.