FAPI text_format field value not being passed to submit handler
Just remove the #value:

$form['description'] = array(
  '#type' =&gt; 'text_format',
  '#title' =&gt; 'description',
  '#default_value' =&gt; '&lt;p&gt;The quick brown fox jumped over the lazy dog.&lt;/p&gt;',
  '#format' =&gt; 'full_html',
);


#value permeates all the way through a form build/validation/submission, and doesn't get replaced with user input.

#default_value will cover the initial value when the form loads.