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I bought a house and it has a Generalaire Humidifier that is not working.  I was told it was the solenoid so I changed that and it wasnt.
 
I checked the wiring from the humidifier to the control board on the furnace and noticed that it was connected to ACC and not HUM...see attached photo.  Theres actually nothing connected to HUM which I thought was strange.

Is it typical for the wires from the humidifier be attached to the ACC and not the HUM?

I don't see a picture attached.

Usually a 120V transformer will connect to the ACC or HUM terminals and step the voltage down to 24V for the humidifier solenoid.  Typically the ACC terminals are energized anytime the furnace fan runs, and the HUM terminals are energized anytime the furnace is heating.  They should have used the HUM terminals.  It's possible the secondary transformer is the problem.

There is likely no reason to use a secondary transformer so you could try removing the two low-voltage wires coming from the humidifier and connect them to the W and C terminals in the furnace.  This will energize the humidifier any time there is a call for heat, if the humidistat is calling for humidity.

Thanks for the reply.  I tried attaching the image but I got a warning saying the upload directory is full.  to contact and admin...I will try to upload later

Thanks for the heads up!  I added more space to the server.

No problem.  I've added the photos hoping that illustrates what I'm talking about

My idea about wiring it directly to W and C won't work because you are wired for two stage heating.

What is the model of the furnace? I would just like to check to make sure the HUM terminals supply 120V on a call for heat.  If so, then you should just have to move the white and black transformer wires from the ACC and neutral terminals to the two HUM terminals.  Then when you turn the heat up, that transformer should get energized and power your humidistat.

It's got to be a faulty, transformer, solenoid or humidistat.

The ACC terminal is usually for a electronic air cleaner or other accessory and should work. If you have a voltmeter/ electrical tester then remove the 2 wires from the solenoid and attach the meter to them. Then start the furnace and when the fan starts turn the humidistat up to maximum and you should have 24 volts AC at the 2 wires. Usually you hear a click when the solenoid opens. Do Not stand in water when doing this but as long as your fingers are dry and you are on carpet or wood 24 volts will not hurt you. If you are uncomfortable then wear disposable latex gloves. I have never been harmed in 30 years of HVAC work but there is a tiny possibility. Use alligator clips on your meter leads to be extra safe. If you have no 24 volts AC then your humidistat may be damaged or the humidifier transformer is damaged or you have a broken 24 wire.

Sorry meant to respond earlier, the furnace is a Lennox Elite Mode number C35-30/36C-2D-1.   

I replaced the transformer, solenoid and still nothing...last thing would be to move the white and black wires to the 2 HuM terminals...just want to wait to see if you think that would be ok

Quote from: Admin on November 22, 2022, 07:02:39 AMMy idea about wiring it directly to W and C won't work because you are wired for two stage heating.

What is the model of the furnace? I would just like to check to make sure the HUM terminals supply 120V on a call for heat.  If so, then you should just have to move the white and black transformer wires from the ACC and neutral terminals to the two HUM terminals.  Then when you turn the heat up, that transformer should get energized and power your humidistat.

It's got to be a faulty, transformer, solenoid or humidistat.

Nevermind! Turned out it was the transformer and the wife who didn't know how to turn the humidifier on from upstairs lol

Thanks everyone for all your help