How do I know if my Aprilaire humidifier is working?

Consumer question:

I just purchased a house which has an Aprilaire Automatic Humidifier Model 600 installed. How do I know if it's working? The control panel has an OFF position and the different humidity levels, but there is no light indicating if it is ON or not.

Aprilaires' response:

Thank you for contacting us with regards to your model 600 Humidifier. When your heat is on and the humidistat (control panel) is set to a level higher than the current level of humidity in your home, the humidifier should be on. The easiest way to verify this is to look at the drain line of the humidifier. During normal operation, model 600 will have a small trickle of water draining from that line. If the humidifier is off, or if the furnace is off, there should be no water draining from that line. Depending on the age of your humidifier, you could have any of several humidistats installed. You can find the owner's manual for all of the 600s released since 2001 online at http://www.aprilaire.com/index.php?znfAction=OwnersManual.

We appreciate the opportunity to be of assistance.

Comments for How do I know if my Aprilaire humidifier is working?

Monday, November 12, 2012 by Chris:: How can I set the Aprilaire 110 so that it comes on when the furnace is running so I can confirm that the water is flowing and the unit is operating?
Thursday, February 14, 2013 by tracy:: have model 600 aprilaire humidifier when heat is on should water always be running through filter? if water is not always running what could be wrong? when put on test/reset the water runs, when turn the dial to a number setting, water stops house feels dry