using h4 to denote offscreen text

Hello I am reviewing the accessibility of a website and have noticed heading tags being used for off screen text that would only be read by a screen reader. I am wondering if this is the proper way to code this. Using jaws I am at the top of content and it reads <h4 class="Offscreen-Text">Start of Errors</h4>

This doesn't seem to be semantic to me, can anyone verify this? thanks