Should I see the UV-C Bulb Lighting up on my Air Purifier?

The quick answer to this is, no. The UV-C Bulb is located horizontally in the unit within a partially enclosed housing behind the filter. Upon activating the UV-C bulb, the external light will turn blue, indicating that it is on, but you will not be able to see the bulb lighting up based on the location of the bulb inside of the unit.

The exception to this are models AC5000 and AC5250PT. These models will show the "glow" from the UV-C bulb given the placement of the bulb in the unit.