This is the header.php title tag:
<title><?php global $page, $paged; wp_title( '|', true, 'right' ); bloginfo( 'name' ); if ( $paged >= 2 || $page >= 2 ) echo ' | ' . sprintf( __( 'Page %s', 'doover' ), max( $paged, $page ) ); ?> </title>
And here's what the theme is using for the page h1 tags:
<h1><?php echo trim( wp_title( '', false ) ); ?></h1>
I don't know that much about PHP but I think forcing the titles or editing that would mess up other features of the theme? I don't like how the title of the site is included in the h1, I'd only want the title to appear.