Is Aprilaire 500M suppose to turn on when furnace motor turns on?
I had it wire to the 24V leads in the furnace cabinet but the only time the water valve turns on to the unit is when I do it manually with the setting dial. Also, what stops the water from running once the filter element gets saturated with water?
Humidifiers - Aprilaire
Answers & Comments
The humidifier should turn on and off with the blower motor of the Furnace. This can be done by wiring the the humidifier to the HUM terminal on the furnace control board and then stepping down the power with a transformer. If the humidifier has it's own tarnsformer then a current sensing relay can be used by attaching it to the blower motors common wire.