Имаш два варианта, да инсталираш добавка System - Header Tags или да пипнеш кода.
Първия:
http://extensions.joomla.org/extensions/site-management/seo-a-metadata/meta-data/14835Втория:
/www/components/com_content/views/article/tmpl/default.php
<?php if ($this->params->get('show_title')) : ?>
<td class="contentheading<?php echo $this->params->get( 'pageclass_sfx' ); ?>" width="100%">
<?php if ($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); ?>[/url]
<?php else : ?>
<?php echo $this->escape($this->article->title); ?>
<?php endif; ?>
</td>
<?php endif; ?>
Modify that part by adding H1 tag.
<?php if ($this->params->get('show_title')) : ?>
<td class="contentheading<?php echo $this->params->get( 'pageclass_sfx' ); ?>" width="100%">
<h1><?php if ($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); ?>[/url]
<?php else : ?>
<?php echo $this->escape($this->article->title); ?>
<?php endif; ?></h1>
</td>
<?php endif; ?>