Question: Is it normal for quiet a bit of water to be running out of my 550, 600, 700 Aprilaire humidifier?
Answer: Yes, It is normal for a small stream of water to run out of the bottom, through the drain tube in the humidifier. This water flow should stop shortly after the humidifier goes off. If the water continues to run more than 5 minutes, you have a not wired the humidifier properly or you have a bad 4040 solenoid valve. Turn the furnace power off with the switch on the side. If the water stops flowing the humidifier is not wired properly. Recheck the wiring diagram and wire properly.