HVAC License New Hampshire: There Is No HVAC License, There Are Four Gas Endorsements and a Scope Pyramid (2026)

There is no such thing as a New Hampshire HVAC license. There is no mechanical contractor license either. Search the New Hampshire Mechanical Safety and Licensing Board's own fee schedule and you will not find the letters HVAC anywhere on it.

What New Hampshire licenses instead is fuel gas fitting, split into four separate endorsements plus a fifth appliance license, each with its own education hours, its own field-experience requirement and its own scope of work. Two more certifications — oil heating and water treatment — exist and are voluntary. And an entire category of work most people file under "HVAC," namely air conditioning and refrigeration, is not a licensed trade in New Hampshire at all.

Getting this wrong is expensive in both directions. Companies over-qualify their people into endorsements they do not need, and under-qualify them for the gas work they do every day.

Who regulates it

The Mechanical Safety and Licensing Board, inside the Office of Professional Licensure and Certification (OPLC), 7 Eagle Square, Concord. Statute: RSA 153:27 through RSA 153:38. Rules: N.H. Code of Administrative Rules, Chapters Mec 100–800, re-prefixed from Saf-Mec by Document #13770 effective December 10, 2023, with the core licensing chapters readopted by Document #14482, effective February 13, 2026 and running to February 13, 2036.

A warning before you read any other guide on this subject: New Hampshire has no plumbers' board, no gas board and no mechanical contractors' board. It has one board covering plumbing, fuel gas fitting, domestic appliances and hearth systems. Guides that name separate boards are describing a structure that does not exist.

What is actually licensed

Here is the complete list of mechanical credentials the board issues, taken from its own published fee schedule:

• Apprentice Plumber
• Journeyman Plumber
• Master Plumber
• Fuel Gas Fitting Trainee
• Fuel Gas Fitter
• Domestic Appliance Technician
• Plumber Water Treatment Business
• Mechanical Business Entity
• Oil Heating Technician Certification

No air conditioning license. No refrigeration license. No sheet metal or ductwork license. No "HVAC technician" license. If the job involves no fuel gas connection and no plumbing, the New Hampshire mechanical licensing chapter does not license it — what governs it is the state building and fire code, local permitting, and the federal refrigerant-handling rules that apply nationwide.

That is why an HVAC company in New Hampshire is really a gas company for licensing purposes. The license follows the fuel, not the equipment.

The four fuel gas fitting endorsements

Mec 305.02 through 305.05 define four fuel gas fitter endorsements. They are not tiers of the same license with a bigger number on top — each has its own scope, and you apply for the endorsement that matches the work.

Fuel Gas Piping Installer

Scope (Mec 305.02(a)). Installation of liquefied propane and natural gas piping, from the point of delivery — the outlet of the first-stage regulator for LP, or the outlet of the natural gas meter — to any and all fuel gas appliances or other gas utilization equipment, including future portions of the gas distribution system located there.

Requirements (Mec 305.02(b)).

• 60 hours of educational training covering basic gas theory and the physical properties of propane and natural gas, plan reading, sizing tables and charts, piping installation including underground and above-ground supply and distribution, purging and initial pressure testing and leak checking, documentation of pressure testing and leak checking including customer notification on odor recognition, and the laws, regulations and adopted codes governing fuel gas piping; and
• 1,000 working hours of on-the-job experience relevant to gas piping installation within 60 consecutive months — of which 500 hours may be credited from relevant field experience installing, servicing and repairing heating-oil-fired equipment.

The catch that is also the shortcut. Mec 305.02(a)(2) requires that a fuel gas piping installer be licensed as a New Hampshire plumber. You cannot come to this endorsement cold. But Mec 305.02(c) then says that notwithstanding any rule to the contrary, a New Hampshire licensed plumber in good standing qualifies for the fuel gas piping installer license once they complete the 60 hours of education alone — no separate 1,000 hours. For a licensed New Hampshire plumber, this endorsement is 60 classroom hours away.

Fuel Gas Installation Technician

Scope (Mec 305.03(a)). Installation of inside and outside piping from the outlet of the gas meter or first-stage regulator, and of residential and non-residential heating equipment systems and water heating systems using LP or natural gas. Specifically: installing the piping from the point of delivery to the appliances; installing the gas appliances and other gas utilization equipment; installing the venting and vent systems, including air for combustion and dilution; and performing safety checks, equipment conversion for the proper fuel supply and required efficiency, and start-up procedures.

Requirements (Mec 305.03(b)).

• 100 hours of educational training — the six piping subjects above, plus appliance installation and clearance to combustibles, combustion, dilution and ventilation air sizing, appliance venting categories and vent material selection and sizing and clearances, placing appliances into service while controlling propane-and-air mixtures for proper combustion, verification of safety controls and devices, and proper use of combustion analyzing equipment; and
• 1,000 working hours of relevant on-the-job experience within 60 consecutive months, 500 of which may be credited from oil-fired appliance or equipment experience.

Ascending from Piping Installer (Mec 305.03(c)). A fuel gas piping installer moving up needs only a 40-hour approved program covering the appliance-and-venting subjects, plus the 1,000 hours.

Fuel Gas Service Technician

Scope (Mec 305.04(a)). Servicing and repair of inside and outside piping from the outlet of the gas meter or first-stage regulator, and of residential and non-residential heating equipment and water heating systems using LP or natural gas. This is the diagnostic and repair license.

Requirements (Mec 305.04(b)).

• 140 hours of educational training — everything above, plus troubleshooting electrical circuits and control devices while measuring electrical quantities with a meter, identifying and testing appliance safety and sensing devices, gas pressure measurement at supply and burner, ignition safety systems including 100 percent pilot safety shut-off and electronic safety shut-off devices, flue gas analysis and carbon monoxide detection, interpretation of appliance wiring diagrams to determine sequence of operation, and heat exchanger inspection and routine service; and
• 2,000 working hours of relevant on-the-job experience within 60 consecutive months, 750 of which may be credited from oil-fired appliance or equipment experience.

Ascending from Installation Technician (Mec 305.04(c)). A 40-hour approved program on the diagnostic subjects, plus the 2,000 hours.

Hearth System Installation and Service Technician

Scope (Mec 305.05(a)). Installation, servicing and repair of LP or natural gas hearth appliances and venting systems.

Requirements (Mec 305.05(b)).

• At least 60 hours of educational training covering gas theory, piping installation and sizing and purging and leak checking, placing equipment into service, hearth installation and clearance to combustibles and ventilation sizing including combustion and dilution air, venting categories and materials and sizing and clearances, hearth appliance diagnostics and troubleshooting, gas pressure measurement, flue gas analysis and leak detection, ignition control systems, and the adopted codes; and
• 2,000 hours of field experience relevant to hearth appliance and hearth venting installation and service, within 60 consecutive months.

Note that hearth carries the same 2,000-hour field requirement as the service technician endorsement on half the classroom hours. It is a narrow scope, not an easy one.

The fifth license: Domestic Appliance Technician

This one is separate from the fuel gas fitter endorsements and is worth understanding because its scope is precisely drawn.

Scope (Mec 305.06(a)). Installation, servicing and repair of LP or natural gas domestic appliances designed specifically for residential use, limited to: residential clothes dryers and their exhaust systems; domestic cooktops and ranges and their venting systems; outdoor cooking equipment; and pool heaters — including the venting systems for which the training and manufacturer certification applies.

Requirements (Mec 305.06(b)).

• At least 40 hours of educational training on gas theory, fixed piping installation and sizing and material selection and above-ground supply, purging and pressure testing and leak checking of piping and residential cooking and clothes-drying appliances, generators, outdoor pool heaters and outdoor fireplaces, placing equipment into service, appliance installation and clearances and combustion and dilution and ventilation air sizing, venting categories and materials and sizing and clearances, and the fundamentals of residential dryer exhaust systems;
• A minimum of 30 hours of factory-authorized certification training specific to the appliances the applicant will install and service, covering diagnostics, troubleshooting, gas pressure measurement and flue gas analysis and leak detection, ignition control systems, following manufacturer specifications, and the adopted codes; and
• 1,000 hours of field experience relevant to the installation and service of those appliances and their venting systems, within 60 consecutive months.

The 30 hours of manufacturer-authorized training is unusual. New Hampshire is the rare state that writes factory certification into the licensing rule itself rather than leaving it to the employer.

The scope pyramid — hold one, get four

This is the most commercially useful pair of rules in the chapter, and it is almost never explained.

Mec 302.07. An individual who meets the qualifications for fuel gas service technician shall be deemed to be qualified as a domestic appliance technician, a fuel gas installation technician, a hearth system installation and service technician, and a fuel gas piping installer.

Mec 302.08. An individual who meets the qualifications for fuel gas installation technician shall be deemed to be qualified as a domestic appliance technician, a hearth system installer and service technician, and a fuel gas piping installer.

So the service technician endorsement is the top of the pyramid and carries all four others with it. For a company deciding what to put its people through, that changes the arithmetic completely: 140 classroom hours and 2,000 field hours produces a technician who covers piping, installation, hearth and domestic appliances. Four separate endorsement tracks would cost far more of both.

And it changes the trainee math too. Under Mec 605.03, gas fitting licensees may employ at any one time no more than two fuel gas fitting trainees for every one licensed fuel gas fitting technician, provided the licensee's endorsement meets or exceeds the level of the work being performed by the trainees. A service technician can supervise trainees doing anything in the chapter. A piping installer can supervise trainees doing piping.

The trainee tier

New Hampshire licenses the trainee. Under Mec 302.01 you may not work as a fuel gas trainee without a registration license, and under Mec 302.02 the minimum age is 16.

The trainee application requires a signed letter from the licensed fuel gas fitter who will be supervising, stating that the sponsor or a licensed fuel gas fitter within the same firm will provide direct supervision of the applicant's work while in their employment; that the sponsor will register the applicant in an approved fuel gas educational and training program for the discipline being trained for; that the applicant will participate in an employee development program in which the sponsor or firm monitors and records hours of actual service, competency levels and completion of the required formal education; and that in the sponsor's opinion the applicant is competent to be trained.

There is also a field-experience shortcut with conditions (Mec 302.11): an applicant submitting hours of relevant field experience obtained within 60 months prior to submission under RSA 153:28, I(a)(1)–(4) and (6) is not eligible for any licensing exam without first completing the minimum hours of formal education for each endorsement applied for, must submit those hours on a sworn affidavit approved by the board before licensure, and must have the hours verified.

The electrician exception, and how narrow it really is

Mec 303.10 provides that the gas fitting license requirements do not apply to a person licensed under RSA 319-C — a New Hampshire electrician — when performing work governed by their license on gas appliances.

Then subsection (b) closes it almost entirely: "This exemption is specifically limited to the operation of the appliance service gas shut off valve."

A licensed New Hampshire electrician may turn the gas off at the appliance service valve to do electrical work. That is the whole exemption. It is not authority to disconnect, reconnect, pipe, vent or service a gas appliance. Any summary that describes New Hampshire electricians as being able to "do gas work on appliances" has dropped the second half of the rule. The full electrical picture is in our New Hampshire electrician licensing guide.

Oil heat and water treatment are voluntary

Chapter Mec 700 is titled "Voluntary Certification of Heating Installers and Heating Equipment Service Personnel." Chapter Mec 800 is titled "Voluntary Water Treatment Certification." Both mean what they say.

Oil-fired heating work is not a licensed trade in New Hampshire. The Oil Heating Technician Certification exists, costs $50.00 to apply, renew or reinstate, and is optional. Water treatment technician certification is likewise optional — although note the separate, and mandatory, Plumber Water Treatment Business license at $250.00, which is a business credential rather than an individual one.

This is worth planning around, because those voluntary oil hours are creditable against the mandatory gas endorsements: 500 hours toward the piping installer and installation technician requirements, 750 toward the service technician requirement. An oil tech in New Hampshire is already a quarter to a third of the way into a gas endorsement.

Fees, terms and continuing education

Published OPLC fees for the gas-side credentials:

• Fuel Gas Fitting Trainee — application $90.00 · renewal $80.00 · reinstatement $90.00 · certificate $20.00 · verification $10.00
• Fuel Gas Fitter — application $190.00 · renewal $180.00 · reinstatement $190.00 · certificate $20.00 · verification $10.00
• Domestic Appliance Technician — application $170.00 · renewal $160.00 · reinstatement $170.00 · certificate $20.00 · verification $10.00
• Oil Heating Technician Certification — application $50.00 · renewal $50.00 · reinstatement $50.00
• Mechanical Business Entity — application $250.00 · renewal $250.00 · reinstatement $250.00

Fees are set by the board and the OPLC and are subject to change. Verify the current schedule with the OPLC before applying.

Terms. Initial individual licenses run two years (Mec 302.03); business entity licenses run two years (Mec 302.04).

Expiry, and the calendar split. Individual fuel gas fitting, domestic appliance technician and hearth system licenses expire every two years on the last day of the month of the licensee's birth (RSA 153:30, I; Mec 402.01(a)). Mechanical business entity licenses expire biennially on the last day of January (RSA 153:29-a, II; Mec 402.02(a)). Two clocks, two calendars. We walk through the consequences in the New Hampshire plumbing licensing guide.

Lapse mechanics. No late fee in the first 30 days, then assessed for each portion of every calendar month after. A one-time $50.00 payment defers renewal fees up to 90 days past expiration if the application and education components are complete. Past 365 days, reinstatement requires passing the licensing examination for each category being renewed.

Continuing education (Mec 404.01). No fewer than 6 hours per endorsement per two-year cycle, from a board-approved seminar provider. For a technician holding a fuel gas service technician endorsement and a master plumber license, that is six hours for each. Seminars are minimum three contact hours in a classroom, and credit is not given for a repeated seminar — you need both separate board-approved three-hour sessions inside your cycle, per endorsement (Mec 404.03(f)).

Where the aggregators go wrong on New Hampshire

Three errors recur on page one, and they are worth naming so you can spot them.

Inventing a testing vendor. New Hampshire's mechanical licensing examinations are administered through board-approved training programs and testing organizations under Mec 308, and the OPLC fee schedule contains no separate statewide examination fee line. Guides that tell you to book a New Hampshire gas or plumbing exam with a national testing company are describing another state's system.

Inventing a home improvement registration. At least one page ranking for New Hampshire contractor licensing states that residential contractors "must register as a Home Improvement Contractor under RSA 332-A." RSA 332-A is titled "Licensing Standards Established" and has exactly two sections: 332-A:1, Licensing Questions Restricted, and 332-A:2, Licensing and Employment of Aliens. It has nothing to do with home improvement contractors, and New Hampshire operates no such registration.

Flattening the endorsements. Descriptions of a single "New Hampshire gas fitter license" with one set of hours miss the four-endorsement structure entirely, and with it the scope pyramid in Mec 302.07 and 302.08 that determines what your technicians can actually supervise.

Frequently asked questions

How much does an HVAC license cost in New Hampshire? There is no HVAC license to buy. The relevant board fees are $190 for a fuel gas fitter license, $170 for a domestic appliance technician license, $90 for a trainee registration, and $250 for the mechanical business entity license. The real cost is the education — 60, 100, 140 or 40-plus-30 hours depending on the endorsement — priced by the board-approved training providers, not by the state. Fees are set by the board and change; verify with the OPLC.

How long does it take? The field-experience requirement paces it: 1,000 hours for piping installer, installation technician and domestic appliance technician; 2,000 hours for service technician and hearth. All must be earned within 60 consecutive months, so hours do age out. A New Hampshire licensed plumber is the fastest case by a wide margin — 60 classroom hours to the piping installer endorsement, with no separate field requirement.

Do I need a license to install air conditioning in New Hampshire? Not from the Mechanical Safety and Licensing Board. Its licensing categories are plumbing, fuel gas fitting, domestic appliance, hearth, and the two voluntary certifications; air conditioning and refrigeration are not among them. Building and fire code compliance, local permitting and the federal refrigerant-handling requirements still apply, and the moment the job touches gas piping or a gas appliance you are back inside the licensed endorsements above.

Does my company need its own license? Yes. Mec 302.05 requires every business entity, corporation, partnership, LLC, LLP and sole proprietor performing fuel gas fitting or plumbing in New Hampshire to hold a mechanical business entity license, and Mec 307.04(a)(3) conditions that license on the company employing a corporate officer or responsible managing employee who holds the specific license for the discipline. That rule is the subject of our New Hampshire responsible managing employee guide.

What this means if you run the company

The gas endorsements are individual credentials. The authority to sell the work is not — it belongs to the mechanical business entity license, and that license only exists while a properly-endorsed licensee sits inside the company as an officer or responsible managing employee. Lose that person and Mec 307.04(b) requires you to stop: the business shall not act as a fuel gas fitter or plumber until a replacement licensed fuel gas fitter or master plumber is in place as the responsible managing employee. There is no grace period written into the rule.

The lawful way to hold that position when you do not have it in-house is to bring a properly-endorsed licensee into the business as a genuine full-time W-2 employee. Not a percentage arrangement, not a flat fee, not per-project, not 1099 — and emphatically not a paper loan of somebody's license, which Mec 607.01(b) prohibits in terms broad enough to cover "any other purpose" beyond pulling permits. That is how The Licensing Company places qualifying agents: full-time W-2 employment, and nothing else.

If the concept is new, start with what a qualifying agent is. For the New Hampshire mechanics, read the responsible managing employee guide and the plumbing licensing guide. To talk through qualifying a New Hampshire mechanical company, see hiring a qualifying agent and our consultation packages, or browse other states.

Last reviewed September 2026. Endorsement hours, fees, expiry dates and rule numbers are set by the New Hampshire Mechanical Safety and Licensing Board and the OPLC and are subject to change. Verify current requirements directly with the OPLC before applying.