Illinois Plumbing Code Practice

The owner is responsible for the maintenance of the plumbing system. This is because the plumbing system is typically considered part of the property and is the owner's responsibility to ensure that it is properly maintained and functioning correctly. The contractor is responsible for the installation of the plumbing system, the plumbing inspector ensures that the system meets code requirements during construction, and the engineer is involved in designing the system. However, when it comes to ongoing maintenance and upkeep, the responsibility falls on the owner of the property.