I got problems getting text back into the summernote editor.
I already tried (but did not work):
$(\"#EDITsummernote\").innerHtml = \'test\';
Insert Text:
$('#summernote').summernote('editor.insertText', 'hello world');
You can use this line if you want to set (paste) HTML code in editor:
$('#summernote').summernote('editor.pasteHTML', 'hello world');
Source code
Bonus
Clear all editor content:
$('#summernote').code("");