Plumbing and HVAC rules in New Hampshire
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
Plumbers in New Hampshire hold master or journeyman licenses from the Mechanical Safety and Licensing Board.1, 2, 3
Heating and cooling licensing
New Hampshire's Mechanical Safety and Licensing Board licenses fuel gas fitters, and certification for oil heating technicians is voluntary. For air conditioning work, ask the contractor which licenses they hold.4
Plumbing and mechanical codes
Your local building department can tell you which plumbing and mechanical codes apply where you live.
Permits to replace a water heater, furnace or AC
Ask your local building department whether replacing a water heater, furnace or AC needs a permit where you live.
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 New Hampshire
Published national ranges for plumbing, water heater, sewer, AC, heat pump and furnace jobs, and a planning estimate for your own job.
Contractors in New Hampshire
119 plumbers and heating and cooling contractors are listed in New Hampshire. 78 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 New Hampshire.” PlumbingInformationSite.com, updated September 27, 2026. https://plumbinginformationsite.com/nh/rules/