My topic has no heading in my Word output

This happens when you accidentally choose the "No Heading" template to base a topic on (right above "Normal" on the "Based on" drop down list). Even though you may then choose another template and save the topic, the Print tab will have no Heading. The Help and Web tabs will have headings, as normal.

Solution

Copy your Heading to the Print tab by clicking on the [...] button beside the Heading on your topic's General tab.