A. In the “Auto” (automatic) position, the blower of your heating system cycles (goes off and on) because it is controlled by the room temperature. In the “On” position the blower runs continuously (independent of room temperature).

Two additional advantages accrue from “ON” position operation. (1) If you have an electronic air cleaner, you get a continuous flow of clean air and (2) Continuous Air Circulation (CAC) prevents the air from stratifying (warm air rising; cooler air falling) that occurs doing the “Off” cycle of a blower that cycles automatically.