Master plumber is the highest professional level of plumbing. Master plumbers work their way up from apprentice to journeyman to master. As a master plumber, your primary responsibilities are to install and to maintain water systems in commercial and residential buildings according to codes and regulations for safety and energy efficiency. Your job duties include sketching and reading blueprints, installing pipes, fixtures, and appliances for water systems like water heaters, showers, sinks, and toilets, and providing service and repairs for those items. As a master plumber, you may take on additional jobs, such as training and supervising apprentice and journeyman plumbers.