The part(s) or condition(s) listed below for the symptom Humidifier not working 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.
Clean Dehumidifier Coils and Filters - Tech Tips from Repair Clinic
Humidifier Leaking? Humidifier Troubleshooting
Humidifier Overflowing? Humidifier Troubleshooting
Humidifier Drum Won't Turn? Humidifier Troubleshooting
Humidifier Fan Not Working? Humidifier Troubleshooting
Humidifier Not Getting Water? Humidifier TroubleshootingThe saddle valve is a small brass water supply valve which is often clamped to a copper household water supply pipe. Over time, the saddle valve can become clogged with sediment or calcium deposits. Because it is difficult to clean a saddle valve thoroughly, and because the replacement cost is fairly low, we recommend replacing the saddle valve if it is restricted.
The humidifier gets its power from the furnace control board. If no power is getting to the humidifier and you've determined the furnace control board needs to be replaced, you will have to use the furnace model number to get the correct part. The humidifier model number will only show parts specific to the humidifier.
Some furnaces have a separate transformer to provide 24 volts to the humidifier. If the water inlet valve is not receiving 24 volts and the contacts in the humidistat are closing as expected, it's likely the transformer has failed and the component will need to be replaced.
Drum-style humidifiers use a drive motor to rotate the drum through the water in the tray. If you’ve confirmed the drive motor is receiving voltage, but the drum is not turning, it’s likely the drive motor is defective. You can use a multimeter to test the motor for electrical continuity to help determine if the component is faulty or not. If the motor tests negative for continuity, you’ll know the motor has failed and will need to be replaced with a new one.
The contacts in the humidistat should close when the dial is set higher than the actual humidity in the room. You can use a multimeter to confirm the humidistat contacts are closing. If the contacts do not close as expected, the humidistat is defective and should be replaced.
A drum style humidifier will use a float to regulate the amount of water entering the humidifier. When the tray fills with water to a certain point, the float will rise up and shut off the water inlet valve. A damaged float may not allow the inlet valve to open at all, resulting in the humidifier not getting any water. Inspect the float to determine if it is obstructed or damaged and replace if necessary.
If the water inlet valve is receiving voltage from the furnace control board but is not opening to provide water to the humidifier, the inlet valve is likely defective and will need to be replaced.
If the water inlet valve is receiving voltage from the furnace control board but is not opening to provide water to the humidifier, the inlet valve is likely defective and will need to be replaced.
