The National Fireplace Institute has training classes and a certification program for fireplace and gas-hearth technology. Those who complete all available certifications get the designation of Master Hearth Professional and are certified for gas hearths, fireplace woodburning, and free-standing stoves.
There are three such possible NFI certifications: Gas Specialist, Woodburning Specialist, and Pellet Specialist. A hearth master is one who has obtained all 3 of these certifications.
While it is not necessarily easy to get NFI certification, it is simple to find the resources necessary to study. Quite simply, the National Fireplace Institute creates the exam from the hearth manual for each certification program.
For the Gas Specialist, you need to purchase and study the latest edition of Gas Hearth Systems Reference Manual. For woodburning, there is a separate Woodburning Hearth Systems Reference Manual. Finally, the Pellet Hearth Systems Reference Manual is for the third certification. As of August of 2011, the books are all in their third edition. In the future, however, just make sure you are purchasing the latest edition, as technology does change over time.
The prices are fairly expensive for NFI manuals and certification exams. For example, if you simply want to purchase the manual, they are $289 each as of the publication date of this article. The exam only is $449, but you can get a discount by purchasing both at the same time. Instead of more than $700, you could get them for $539.
Alternatively, you could get an exam and online study course for $559. The biggest discount may be to get the exam, manual, and online study course. When purchased together, all 3 are $579.
Caution: NFI states that even years of work experience on hearth systems may not be enough to pass the certification exams and become a hearth master or other NFI-certified professional. The organization says that study of the manual is recommended for all test takers.
The same goes for live training. You may attend a National Fireplace Institute review course in various areas throughout the United States. However, these are generally just reviews of the manuals and will not totally prepare you to become a hearth master.
Resources:
NFI Price List
NFI Gas Hearth, Woodburning and Pellet Certification Procedures
Map to Find National Fireplace Institute Certification Review Courses