Plumbing and HVAC rules in Colorado

In Colorado, a plumbing business registers as a plumbing contractor with the State Plumbing Board, and plumbers hold master, journeyman or residential licenses.^{1, 2, 3}

Denver issues its own certificates for heating and ventilating contractors and supervisors. Ask your city or county whether it licenses heating and cooling contractors.⁴

Colorado's plumbing code, a statewide minimum set by the State Plumbing Board, is the 2024 International Plumbing Code and the 2024 International Residential Code's plumbing chapters, with state amendments.⁵ Colorado has no statewide mechanical code: the state adopts the International Mechanical Code only for state buildings and some types of facilities, and local governments adopt their own.⁶

Colorado's plumbing code requires a permit to replace a plumbing system, and only leak repairs and clearing stoppages are exempt. With no statewide mechanical code, permits for heating and cooling work are local.⁵

If your home has a backflow preventer, your water utility can tell you whether it needs testing and who can test it.