Is is true <h1> tag should not have more than 1 on every page for SEO?

Every pages on the header, it includes and <h1> tag. Website Name which show an image from logo class, like this:

<div id="header">
  <h1 class="logo">
     <a href="#">Website Name</a>
  </h1>
</div>

and I also include <h1> on the contact page, help, etc and article page for example:

<h1>Contact Us</h1>
<h1>Name of the Article Title here</h1>

On the homepage, it just has one <h1> for the logo Site Name... other pages have 2 <h1> tags