Honeywell he220 humidifier problems
Try removing the cover, and manually cycling on the controler switch? Does the solenoid click on, next to the humidifier (the unit with the water line running through it, with wires coming out of it)? If it does click on, is water running down the water pad? It doesn't necessarily drain water when it's working correctly. All of the water SHOULD be getting evaporated into the air return duct.
If it's clicking on, but no water is running out, you should check the water supply saddle valve and make sure it wasn't turned off during servicing.
If it's not clicking on, you should test that you are getting voltage (12v-18v DC) to the solenoid. If you're not, check all wiring connections and make sure they're tight. If you still don't get power, you have either a problem with your control unit/humidistat, your DC power supply, or the control board on your furnace. You may need to call a HVAC technician at that point, depending on your comfort level/skill level in that regard.
When you say the solenoid "stays hot" do you mean it's physically hot to the touch? Hotter than the water lines running into it?
If the solenoid is getting hot, it probably has a bad coil, and if you continue to operate it, you will probably burn up your DC power supply.
If you're getting voltage, you have water pressure, and the solenoid is still not opening, replace the solenoid.
on Jan 06, 2013