Plumbing and HVAC rules in Hawaii
What the state says about plumbing and heating and cooling work, with the page each rule comes from. It's a summary of the published rules, not legal advice, and your city or county can have rules of its own.
Checked September 23, 2026
Plumbing licensing
A plumbing business in Hawaii holds a C-37 plumbing contractor license from the Contractors License Board, and plumbers hold master or journeyworker licenses from the Board of Electricians and Plumbers.1, 2, 3
Heating and cooling licensing
A heating and cooling business in Hawaii holds a C-52 ventilating and air conditioning contractor license from the Contractors License Board.2
Plumbing and mechanical codes
Hawaii's State Building Code Council doesn't list a mechanical code among the codes it has adopted.4
Permits to replace a water heater, furnace or AC
In Hawaii, the State Building Code Council adopts the codes, and each county adopts them with its own amendments and runs permitting. Permit rules are set by the county.4
Backflow testing
If your home has a backflow preventer, your water utility can tell you whether it needs testing and who can test it.
Sources
What plumbing and HVAC work costs in Hawaii
Published national ranges for plumbing, water heater, sewer, AC, heat pump and furnace jobs, and a planning estimate for your own job.
Contractors in Hawaii
159 plumbers and heating and cooling contractors are listed in Hawaii. 90 hold an active USDOT registration. Browse them by county, or ask for quotes and we'll pass your job to contractors near you.
Cite this page
“Plumbing and HVAC rules in Hawaii.” PlumbingInformationSite.com, updated September 27, 2026. https://plumbinginformationsite.com/hi/rules/