I have a Bryant 355 CAV with Evolution control and Aprilaire 600a whole house bypass humidifier. The humidifier is hooked to the Evo with no humidistat.

In heating mode I want to set the target humidity at approx 33% ( in auto operation). However, I can't seem to select a target humidity of lower than 45% in basic or advanced modes. I can select whatever target I want in manual mode however.

I called my installer and he said that this is normal. It doesn't seem logical to me.

Is it normal?