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

Washington does not license HVAC technicians or journeymen as such; there is no state HVAC, mechanical or refrigeration trade license, so an out-of-state HVAC journeyman license has nothing to transfer to and is not needed to work for a registered contractor. What Washington does require is an electrical certificate for the electrical side of HVAC work: the Department of Labor & Industries issues the HVAC/Refrigeration (06A) specialty electrician certificate for wiring and line-voltage components within HVAC and refrigeration equipment, and the narrower HVAC/Refrigeration restricted (06B) certificate for low-voltage and small circuits. The 06A requires 4,000 hours of supervised experience as an electrical trainee plus 48 hours of classroom instruction and a PSI exam; the 06B requires 2,000 hours and 24 hours of classes. L&I has an electrical reciprocity agreement only with Oregon and only for the general journey level (01) certificate, so out-of-state HVAC technicians document their hours on L&I's out-of-state experience application and take the specialty exam. Federal EPA Section 608 certification is required to handle refrigerants; gas piping and boiler work fall under separate plumbing and boiler programs.