The part(s) or condition(s) listed below for the symptom Humidifier not draining are ordered from most likely to least likely to occur. Check or test each item, starting with the items at the top of the page.
The drain hose might be kinked or clogged. First check to make sure the drain hose is not kinked between the humidifier and the drain source. If the drain hose is not kinked, then it might be clogged. Unclog the drain hose by removing it from the drain pan and blowing compressed air through it to clear the obstruction.
The outlet of the humidifier drain pan may be clogged with mineral deposits. To clear the drain outlet the front panel or housing can be removed to access the port to the drain hose. Use a small Flathead screwdriver to gently clear the deposits from the pan outlet. In some cases, the pan can be removed from the unit for clearing & cleaning.
The water evaporator pad might be clogged with calcium and other mineral deposits. Once the water evaporator pad is clogged, the water rides along the top of the pad and drips down outside of the water collection tray at the bottom. If water does not exit properly check the water evaporator pad and replace as needed.
The water distribution tray sits at the top of the water evaporator pad. It is designed to direct the flow of water over the evaporator pad so that the water drips evenly into the pad. If the distribution tray is out of place, clogged, or cracked, water will not drip into the water evaporator pad.
The water supply line might be leaking. Check for a loose or corroded fitting at the water inlet valve or float. Inspect the water line from the water inlet valve to the water evaporator pad if the humidifier has one. These water lines can get brittle over time and crack or break.