Moving to New Hampshire as a journeyman HVAC technician: every state's rule

New Hampshire does not license journeyman HVAC, air conditioning or refrigeration technicians at the state level, and the Office of Professional Licensure and Certification (OPLC) has no board for the trade; its Mechanical Licensing Board, despite the name, regulates only fuel gas fitters (installation, service, piping, domestic appliance and hearth technicians, plus trainees), plumbers and mechanical business entities, and offers a voluntary $50 Oil Heating Technician certification under RSA 153:16-b. The plumbing statute expressly exempts plumbing done in connection with the installation of heating, cooling, air conditioning and domestic water heating systems (RSA 153:36, VII), so an HVAC technician needs no plumber license either. No New Hampshire city or town was found to license HVAC technicians; local building departments issue mechanical permits but do not require a personal HVAC credential. What an out-of-state technician does need is a Fuel Gas Fitter license before connecting or servicing natural gas or propane furnaces, boilers or piping: the categories cost $198 for two years ($176 for domestic appliance), require 40 to 140 classroom hours, 1,000 to 2,000 on-the-job hours and a 70% score on the Prov exam, and an out-of-state gas or plumbing license only makes the holder eligible to sit that exam (Saf-Mec 302.14); OPLC's endorsement rule Plc 313.34 covers the gas fitter categories in principle but the qualifying-jurisdiction lists are still 'TBD'. An out-of-state journeyman HVAC license itself has no New Hampshire equivalent to transfer to. Federal EPA Section 608 certification is required to handle refrigerants.