Dear pfchute !
You can do it following way below :
Open default.php file in templatesja_zeolitehtmlcom_contentarticle folder, find following code section at about line 19 :
<h2 class="contentheading<?php echo $this->params->get( 'pageclass_sfx' ); ?>">
<?php if ($this->params->get('link_titles') && $this->article->readmore_link != '') : ?>
<a href="<?php echo $this->article->readmore_link; ?>" class="contentpagetitle<?php echo $this->params->get( 'pageclass_sfx' ); ?>">
<?php echo $this->escape($this->article->title); ?>
</a>
<?php else : ?>
<?php echo $this->article->title; ?>
<?php endif; ?>
</h2>
change to :
<h1 class="contentheading<?php echo $this->params->get( 'pageclass_sfx' ); ?>">
<?php if ($this->params->get('link_titles') && $this->article->readmore_link != '') : ?>
<a href="<?php echo $this->article->readmore_link; ?>" class="contentpagetitle<?php echo $this->params->get( 'pageclass_sfx' ); ?>">
<?php echo $this->escape($this->article->title); ?>
</a>
<?php else : ?>
<?php echo $this->article->title; ?>
<?php endif; ?>
</h1>