 Upon request, to become a licensed master plumber, he or she must attend four years of technical school and work 2,000 hours per year under a master plumber to qualify to take the journeyman license test in the state of New Hampshire. After achieving this license, the journeyman plumber must work full time for at least an additional six months before qualifying to test for the master license. And to maintain either license, the plumber must attend yearly educational seminars.