Humidifier mis-wired

Old 12-06-03, 06:50 PM
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Location: Skillman, NJ
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Humidifier mis-wired

We just bought a house and the humidifier does not work.
My husband took it apart and noticed it appeared to be mis-wired.
He cleaned out the solonoid valve and would like to wire it back in correctly.
We have an Aprilaire Model 440. What would be a typical wiring in method. I understand it should turn on when the furnace turns on.

Aprilaire's web site does not give much technical data or help.

Are there any diagrams out there that would be helpful.
Old 12-06-03, 08:54 PM
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that unit was replaced by the 600, and looking at the wiring diagram it looks as though there is a transformer in the humidifier. therefore we just need to complete the circuit with a switch that tells the humidifier that the heat is on. generally, one side of the transformer will go to the humidistat, then leave there and go to a model 50 current sensing relay and then to the solenoid, then back to the other side of the transformer. this will allow the unit to humidify only when a) the humidistat is calling and b) when the fan is energized in heating speed.

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