What is the smell for these??

Out of the package, mine smelled like plastic. Once you add the scent oil inserts (sold separately), the smell changes.

How often should you replace the warmer itself? I understand when to replace the oils.

It seems after I go through about 3 of the scent cartridges, that I start getting this burned smell instead of the nice fragrances. I have invested A LOT in these glade products, 14 warmers and many different scents that once smelled quite nice. Just imagine a beautiful fragrance that has been heated too much, the oil gets that burning smell, and then the entire house smells like that. I have removed all of these worthless devices. And another thing, the scent control knob doesn't really work, and acts like a false sense of savings to the consumer.. I would advise to stay away from this GLADE PRODUCT. It doesn't work like they say it does. Go figure.

Does this have a fan?

Great question. Our Glade® PlugIns Scented Oil does not have a fan. If we can be of further assistance, please don’t hesitate to give us a call at 1-800-558-5252 (Monday through Friday 8 AM to 6 PM CST) and provide reference number: 019734803A.