How to Fix a Whole House Humidifier




Posted in WorkshopRepair

Introduction: How to Fix a Whole House Humidifier

Fix your own whole house humidifier and save money.



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    I'm not always getting 24v!? most times i get 19-21 volts going to the humidifier.. any ideas how i can regulate this?

    5 replies

    Where are you measuring this voltage? The humidifier should be powered with 120 Volts AC. In what way is your humidifier not working? What are the symptoms?

    If you look at my video, when I have the cover off the humidifier, you can see a small circuit board on the right hand side. It has a transformer on it to supply 24 volts. My guess is that you need a new circuit board. Find the part number and google for it. I think it might be this one.

    Ok thx, any chance that my nest is demanding more out of the board? (Nest is not wired to control humidifier)..

    If your Nest thermostat is not connected to the humidifier then it won't draw down the voltage. The humidifier fan runs on 120VAC and the little board makes 24VAC to go out to the humidistat and control the valve.

    Final thought before I buy a board... apparently nest can Run the humidifier directly every time the heat turns on... the question remains wether the board will supply the 24v... could it be the humidistat is the problem? That will be my test tonight... thx for all your help...

    Hi There, I'm am measure the voltage coming from the humidifiers thermostat to where the solenoid was.. I have the thermostat wide open with the furnace running, i get about 19-21 volts... occasionally I get 24 volts and i hear the solenoid click....the current issue is that the solenoid is not opening and no water is going through it, i've purchased two different solenoid thinking one was faulty until i realized the voltage seems to be the problem..? thanks