I have a carrier gas furnace that has a Mister 50 humidifier that was installed several years ago. The humidifier has worked fine for the last several years, however when I turned it on this year it failed to work. The humidifier has a solenoid that you can hear click when the humidistat turns it on, and it appears that for some reason the solenoid is not engaging. The unit is controlled by a humidistat with a knob for adjusting humidity settings, as well as a thermostat in the hot air plenum that turns the unit on when the air reaches a certain temperature. You can hear the humidistat click when you adjust the dial, and the thermostat clicks as well, but the solenoid does not click and no water flows.

Do you think it is a bad solenoid or some kind of wiring problem? The unit is wired directly to the fan control unit in the furnace. Should I check somewhere for voltage? The humidifier is a 24V model. Any help would be appreciated.

Usually these units have a orifice installed in the selonoid or discharge water line to regulate water flow. That should be checked since the selonoid is activating(click).

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