Help troubleshooting a home humidifier

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LittleLebowski

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No fuses out, no electrical issues that I know of. I have opened up the water line as much as I can without breaking something, tried different settings on the dial, all to no avail. No water flows to it.

I have attached pictures of everything I see.

















 
Turn the dial to test mode. Can you hear the solenoid open up and send water through the line? Does the yellow light turn on? Google aprilaire 600 manual and you can find the circuit board troubleshooting guide
 
Just shut off all power to the humidifier and the furnace, got the solenoid valve apart and the metal parts soaking in a mixture of baking soda and vinegar.

After that, I'll double check all wiring using the manual.
 
Vinegar is acetic acid. Baking soda is sodium bicarbonate. One is a base, the other an acid. You're making a fizzy mess. Since you want to get the alkaline (base) deposits off of the parts, you want to just use the vinegar or lemon juice or Lime-Away. Putting the baking soda in there is just neutralizing the acid before it can do much good on the parts.
 
Probably either the solenoid or the orifice in the solenoid. I ended up eliminating the orifice in my solenoid and using the shut of valve to meter the water flow. It probably wastes a bit of water but it still works. It is a simple device. When it powers own the solenoid opens. You could check for power at the solenoid but I would bet on plugged orifice.

You should be able to feel the solenoid click when you turn the dial from off to test or get it above the humidity set point.
 
I've got an Aprilaire w/ slightly different controls but as @Streblerm suggests I'd suspect the solenoid valve. Mine went out a few years ago. If you've got a Volt/Ohm meter measure if its getting 24VAC, if so it's either plugged on the valve/orifice end or the solenoid coil is bad either open and shorting turn-to-turn. Look around on the web and you may be able to find a generic replacement. OEM will be expensive AF. Put simply, if you've got water to the solenoid and voltage to the solenoid and still no water flow it's the culprit. If you're lucky its mineral deposits in the jet/orifice but probably not.
 
If u have water at the solenoid and it clicks when u turn the knob to test it's a plugged orifice which is east to fix. If the solenoid doesn't click it's either the humidistat solinoid or transformer if u have one and if all is clear and it clicks then it's possible that you broke the saddle valve off in the water line and it's stuck shut.

I do hvac for a living
 
I've got an Aprilaire w/ slightly different controls but as @Streblerm suggests I'd suspect the solenoid valve. Mine went out a few years ago. If you've got a Volt/Ohm meter measure if its getting 24VAC, if so it's either plugged on the valve/orifice end or the solenoid coil is bad either open and shorting turn-to-turn. Look around on the web and you may be able to find a generic replacement. OEM will be expensive AF. Put simply, if you've got water to the solenoid and voltage to the solenoid and still no water flow it's the culprit. If you're lucky its mineral deposits in the jet/orifice but probably not.

I tested for 24v on the red and white lines to the left in this picture, right above the "24 VAC" and got no voltage.

 
The humidifier shouldn't run unless the heat is on cause u don't want it to run in ac unless it's wired weird and it should be wired to a transformer in the furnace or a terminal on the circuit board labeled hum or to the w1 on the thermostat wires in the furnace
 
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