A:Answer Yes, you can. When you use that button after turning on the power, the display says "ON".
This is a good slow cooker and part of the reason is the even heat that comes through a heating "plate" rather than the heating ring around the insert that some use.
My lid does not sit completely flat on the ceramic insert but it turns out that it does not matter. It doesn't evaporate a lot of fluid since the heat is so low.
Very easy to use and so far, reliable.