Whenever I turn on the heat and the furnace fan stars working the water from humidifier just runs and runs non stop... and stops only when I turn the fan off or it turns by itself... It was never like that. It used to drains some water once in a while but not non stop. Its Aprilaire humidifier. If water runs just through humidifier all times does it mean that I just waste water and the bill is going to be more than usually?
Thank you

You need to service the unit. New pad and orifice in the valve should do it.