This is really not a theme issue – the control is entirely done using regular WordPress options.
Comments are controlled in the Dashboard Settings->Discussion page. There are quite a few options available, but if you want to disable comments by default for posts and pages, select the appropriate options on that page. (Unchecking the first 3 boxes will do it.) Don’t forget about trackbacks and pingbacks because they can generate “comments” as well.
via Weaver Theme Help.