I have seen the phrase "certified chimney professional" mentioned on this site and want to give clarity to the subject.
Currently, the chimney industry has 3 phases of certifications:
The Chimney Inspector www.gotofire.com
The Installer (hearth Appliances) www.nficertified.org
All of these require a certain level of committment to the area in which one is being certified. The best way to have a full understanding of a chimney to obtain more than one certification.
Always verify someone credentials, it takes just a few seconds on the internet.