Wiring a Humidifier to a Furnace Blower | DoItYourself Typically, a furnace blower’s function is to get rid of the moisture within the area that it provides heat to.Furnace blowers are equipped with hot metal tubes that make it possible for the moisture to get “flushed out.” When air circulates the area and goes right into the heat exchanger, their exposure to the hot metal tubes removes the moisture. How to wire humidifier to run with blower - hvac-talk Feb 04, 2015Hello, Newbie here. My humidity level in my home is quite low, in spite of a furnace mounted Aprilaire power humidifier. I'd like to change the wiring so that the humidifier runs with the blower, not exclusively with a call for heat. The house is below 30% RH and it's quite dry. No moisture on the windows, so I know we need to get the RH up!