Installing water systems is a job for a plumber, which is someone who specializes in the installation and maintenance of pipes and fixtures used for water distribution and waste water disposal. Plumbers are responsible for installing water systems, such as water heaters, pumps, and other related equipment. They also inspect and repair existing systems, as well as install new systems. Plumbers must be knowledgeable about local building codes and regulations, and have the necessary tools and skills to complete the job.