are you simply trying to ensure the heating elements are working? I don't think you have a snake in there yet, correct?
If yes to both - turn up higher, to 89 or something, then temp test to see what you are getting. That would ensure the heating elements are triggered to turn on.
You have it set to 80 and it's already 82, so there's no reason for anything to heat up because it's already above your desired temp.