said by SuperNet9:
So the manual one is the old one and should work?
The one attached to the humidifier works...
Now it says automatic what does that mean?
So is my humidifier automatic and I don't need to do anything?
The manual one - probably was left in place when the furnace company replaced the humidifier. I can't tell over the internet but I'm willing to bet it's not connected to your humidifier anymore and the one in the top photo is controlling your humidifier.
The automatic one is just that - set it to 5 and see how the humidity regulates in your house. I purchased a Radio Shack indoor temperature/humidity monitor years ago to track my humidity as the temperature changed here in Minnesota and I think I eventually upped mine to 6. I've got an older house that isn't well insulated and has a few air leaks.
I did find the chart from my old Aprilaire humidity controller and it went like this based on outdoor temperature and indoor humidity:
Dial set to 5: -10 Degrees, 20%; 20 Degrees, 35%; 40 Degrees, 45%
Dial set to 6: - 10 Degrees, 25%; 20 Degrees, 40%; 40 Degrees, 45%
If you have too much indoor humidity on really cold days it will condense and drip all over your windows. That's the beauty of the automatic humidistat; as the outside temp drops it backs off the indoor humidity and prevents condensation on your windows.
Hope this helps.