Water to the soleniod, soleniod value activates, small drop of water comes through but nothing more. What do we do?

yes, the water will flow to quickly without it. you can use a very small dill bit to clear it. if it flows to fast you can control it using the shut off valve. hope this helps.

the value would have been stuck inside the white cap, so when you press the stick with the spring, the head of the valve should stick out. If this does not work, just remove the spring and the black stick from the value, water should come out

the value would have been stuck inside the white cap, the valve rim should come out like an umbrella out of the cap.

Valves do go bad, but I had the same issue and it was the inlet orifice that was plugged.
To fix: Turn off the water supply. Disconnect the water inlet line to the solenoid. The water inlet line connect to ~ 1" long piece that goes into the solenoid. Unscrew the water inlet piece and remove it from the solenoid. Check it for water flow - water should slowly drip out the small orifice at the soleniod side. There is a pin-hole sized orifice on the solenoid side and it doesn't take much to plug it. There is also a narrow cone-shaped filter inside the inlet piece. You can use tweezers to remove the filter and & use a safety pin or sewing needle to clear the orifice. Check the filter, clean it if necessary, and reinstall the filter. Now check for water flow thru the part before reinstalling. Reconnect the water inlet line and turn on the water supply. Turn your humidistat to trigger the humidifier. You should see water flowing through the drain tube.

I has the same problem with my HE360 unit. The unit was in fact miswired. The head unit red wires were connected directly to the blue solenoid wires, and activated the solenoid without any signal from the humidistat. As soon as the unit is plugged inn, the water starts running without any signal to the unit. If your unit is miswired, the soleniod blue wires need to be cut and connected to the red crimp connectors.

This sounds like, the 550 transformer is not connected to the blower motor power connection (in parallel)

That would the the 24volt soleniod valve that the water line attaches to. Steve

If you are talking about the water line at the water soleniod valve, it is not a o-ring. It is called a ferrel. Any hardware store such as ace will have them in the brass fittings area. It will be 1/4". If your water line is copper you will have to loosen the nut and slide it up out of the way and cut the old ferrel off. The same with plastice tubing. the only difference is that with the plastic tubing you will also need to get the brass insert sleeve as well. Less than a dollar total. to install, slide the ferrel over the tube, if plastic do the same then insert the brass sleeve into the tubing. Slide the tube into the valve till it stops. Then slide the ferrel down till it stops. then slide down the nut and tighten till snug. if it leaks after tightening snug it a little more. But be gentle, its a one shot deal because it locks in place and you will have to cut it off and start with a new one again. Also when you cut the tubing cut off as close to the ferrel so you dont run short on tubing to reconnect. hope this helps

Loosen the brass fitting where it connects to the soleniod valve. If water comes out your saddle valve is ok. Carefully retighten this fitting. With the humidifier turned on loosen the first fitting down stream from the valve see if water comes out. if it does turn the humidifier off and see if it stops, it should. That will tell you the the valve is ok then, just clean the filter and the oriface. if it does not turn on and off check the wiring. if ok replace the valve.
Good luck

Check the filters and the fan blade it may have come loose. Do you still hear the motor running? Get me the model number on the unit. Sorry it took so long to get back to you I have been sick the past few months.