How to remove default 'search' text form search form
The Search text in input is created by jQuery from any where. When I search through the JavaScript files, I find the following file:

file : /sites/default/modules/hg/sw_tweaks/js/sw_tweaks.js


The code

//Search Bar @ Top of Home Page
    $(function () {
      $('#edit-search-block-form--2').val("search");
    });
    jQuery('#edit-search-block-form--2').click(function () {
      jQuery('#edit-search-block-form--2').val('');
    });


Try to remove this code.
I hope this helps you or help you finding the problem.