The answer to 'why is my humidifier freezing up' is that a frozen humidifier is usually caused by low water flow or low humidity levels. This can happen when the water supply line is clogged, the water filter is dirty, or the humidifier settings are not properly adjusted.
Some common symptoms of a frozen humidifier include reduced or no mist output, visible ice buildup on the unit, and the humidifier cycling on and off more frequently. To fix a frozen humidifier, you'll need to clean or replace the water filter, check for clogs in the water line, and ensure the humidifier is set to the right humidity level for your home. If the problem persists, you may need to call in a professional HVAC technician to diagnose and repair the issue.