DRAIN FITTING ON THE BOTTOM OF THE HONEYWELL FURNACE HUMIDIFIER RUNS ON THE OUTSIDE OF THE PLASTIC PIPE AND ENDS UP ON THE BASEMENT FLOOR

SOURCE: Continous ware flow on Honeywell HE220A Humidifier

I am having the same problem. I have had my humidifier for about 5 years now and I just started having the problem where the water continuously flows through the solenoid. I took apart the solenoid by removing the fittings from both sides. When I did that, I noticed that there was a hole in the metal that allowed me to see through to the other side. Apparently, it had corroded and and broken through, allowing the water to pass through the solenoid without really going through the valve within the solenoid. There are several sites that sell replacements for about $70, which is not cheap, but cheaper than buing a new humidifier for $120. Here is one site I found: http://www.iaqsource.com/product.php/honeywell/32001639-002/?product=112783&category=1142

SOURCE: cleaning a furnace humidifier steel filter?

Most water panels are generally replaced once a year on flow through humidifiers.

SOURCE: When furnace cycles on the humidifier overflow

If the water stops when the heater is not running then the humidifier is working fine. I know it seems like alot of water but that's how it's designed.

Testimonial: "Thanks"

SOURCE: Honeywell HE260 leaks somewhere

Neither, even if the solenoid or humidistat stick, it should always drain properly. Is the unit mounted on the cold air return duct or the supply plenum? If it's mounted on the supply plenum, the water panel might be getting blown forward and spilling the water. High efficient furnaces also can leak water on the floor if its drain is restricted. If hum. is mounted on return duct make sure drain is clear by blowing through it. On Honeywell hum's I've seen the rubber hose from the solenoid valve to the distributor tray leak too, check the rubber 1/4" hose.

SOURCE: The clear plastic drainage tube

One way of removing the gunk is to disconnect the tubing from the humidifier and use a flexible and thin rod that will fit in the tubing and try to dislodge it, or you can try using a shop vac and see if the suction pressure will remove it. If the tubing is really clogged then sometimes it's better to just replace the vinyl tubing with pvc pipe and drain it to the floor drain, I always prever pvc pipe over vinyl tubing when it comes to drain lines for humidifiers.