Add something simple like **No answer accepted ** learn more(link)
There are several questions where generally a new user posted a question, an answer has many up votes, the poster comments something like, "Great that works, thanks alot" and it is not accepted. If somebody new visits the site and asks a question - it may not be clear to them that you can select an answer as accepted.
If no answer has been accepted (and there is one answer) - when the question poser views the pages where it currently states 7 Answers add text similar to:
You have currently not accepted an answer learn more(link)
- or -
No answer accepted learn more(link)