How to Get an HVAC License in Connecticut (2026 S-1, D-1 and B-1 Guide)

There is no such thing as a Connecticut HVAC license. That is not a technicality, it is the single most expensive misunderstanding in this state, and it is why HVAC techs routinely spend two extra years qualifying for a credential far broader than the work they actually do.

What Connecticut has instead is a matrix of heating, piping and cooling licenses issued by the Department of Consumer Protection, each with a hard-edged scope and its own hour requirement. Pick the right code and you may need 432 classroom hours. Pick the "safe" unlimited one and you need 576 classroom hours and 4,000 more hours of field time. Pick the wrong one and you cannot legally touch half the equipment on your service van.

Here is the whole matrix, decoded, current for 2026.

Who regulates HVAC work in Connecticut

The Connecticut Department of Consumer Protection (DCP), Occupational and Professional Licensing, licenses heating, piping, cooling and sheet metal work. The Heating, Piping, Cooling and Sheet Metal Work Examining Board advises DCP on examinations and licensure.

The governing law is Chapter 393 of the Connecticut General Statutes, with "heating, piping and cooling work" defined at § 20-330 and the general license structure at § 20-334a. Every license below is issued in a matched pair: a contractor license (odd-numbered, requires two years as a properly licensed journeyperson) and a journeyperson license (even-numbered, requires completion of a registered apprenticeship program), where the journeyperson may work only in the employ of a contractor licensed for that work.

And one point that determines everything else about how HVAC businesses operate here, DCP states it on its own application page: "Only individuals can apply, company applications are not accepted."

The Connecticut HVAC license matrix

The unlimited license

• S-1 Unlimited Heating, Piping and Cooling Contractor / S-2 journeyperson. May do all heating, piping and cooling work defined in § 20-330, including any sheet metal work defined within § 20-330. This is the top of the ladder and the broadest scope available.

The license most HVAC techs actually want

• D-1 Limited Warm Air, Air Conditioning and Refrigeration Contractor / D-2 journeyperson. Installation, repair, replacement, maintenance or alteration of any warm air, air conditioning and refrigeration system, including the piping needed to convey heating or cooling media and associated pumping equipment. LP gas from containers, natural gas piping, approved gas appliances and gas utilization equipment are included. Sheet metal work is included as it pertains to the limits of the credential.

  The trap: "This license does not include the installation or servicing of oil burners of any size." Not small ones. Not as a favor. None. If your service area has oil heat, and large parts of Connecticut do, a D-1 alone leaves you turning down calls or working illegally.

Cooling and refrigeration only

• D-3 Limited Cooling Contractor / D-4 journeyperson. All refrigeration systems in food storage, air conditioning, or special process systems. Excludes LP gas from containers, natural gas, and servicing of oil burners of any size. This is the commercial refrigeration and cooling lane, narrower than D-1 on the fuel-gas side.

Burners

• B-1 Limited Gas and Oil Burner Contractor / B-2 journeyperson. Gas or oil burners for domestic and light commercial installations only, defined as consuming five gallons or less per hour, or systems with a total heating load not exceeding 500,000 BTU. Includes piping for petroleum-based fuels, alternative fuels, tanks and related equipment, LP and natural gas piping, and approved gas appliances.
• B-3 Limited Gas and Oil Burner Contractor / B-4 journeyperson. Same work, any size and any capacity, no BTU or gallons-per-hour ceiling.

Gas piping only

• G-1 Limited Heating, Piping and Cooling Contractor / G-2 journeyperson. Gas piping systems and approved gas appliances, gas utilization equipment and accessories for LP gas from containers and natural gas. Sheet metal included within the limits of the credential.

Boilers, steam and hydronics

• S-3 Limited Heating, Cooling and Piping Contractor / S-4 journeyperson. Heating systems, boilers, apparatus and piping for the generation or conveyance of steam and associated pumping equipment; petroleum and alternative fuel piping, LP and natural gas; hot, chilled and condenser water and steam piping in air conditioning systems. Excludes refrigeration systems, affiliated piping and refrigerants as used within air conditioning systems.
• S-7 Limited Contractor / S-8 journeyperson. Similar heating, warm air, boiler and steam scope, but restricted to buildings not over three stories high, with a total heating load not exceeding 500,000 BTU and steam pressure not exceeding 15 pounds. Excludes refrigeration systems and refrigerants.
• S-9 Limited Heating Cooling Contractor / S-10 journeyperson. The S-7 building and load limits, plus cooling installations up to 35 tons per system. For residential and light-commercial firms that do both sides of the system, this is often the right answer.

Large-system operation

• OE-2 Limited Operating Engineer Journeyperson. Operation, manipulation, adjustment, control and monitoring, of heating, air conditioning and refrigeration systems and boilers above a threshold: steam or water boilers over 15 psi, or AC/refrigeration systems aggregating more than 50 horsepower (or the kilowatt equivalent) or 200 pounds of refrigerant. Permits incidental maintenance directly on or adjacent to the operating equipment. Does not permit any replacement or revisions to existing piping of any system type. Work must be performed in the employ of a properly licensed contractor, or as an employee of a building owner on premises the employer owns or leases.

Process piping

• PP-1 Limited Process Piping Contractor / PP-2 journeyperson. Piping or tubing conveying liquid or gas used directly in the production of a chemical or a product for human consumption.

One genuinely useful thing about Connecticut's structure: every limited license in this family "shall include sheet metal work as it pertains to the limitations of this credential." You do not need a separate sheet metal license to do the ductwork that belongs to the systems your license already covers.

The hours: why picking the right code saves you years

DCP publishes the requirement chart on the equivalent-experience application path. As with plumbing, the on-the-job number is not all apprenticeship, it is apprenticeship hours plus two years (counted as 4,000 hours) working as a properly licensed journeyperson:

• S-1 Unlimited Heating, Piping and Cooling: 8,000 + 2 years (4,000) = 12,000 OJT; 576 classroom
• S-3 Limited Heating, Piping: 8,000 + 4,000 = 12,000 OJT; 576 classroom
• S-7 Limited Heating: 8,000 + 4,000 = 12,000 OJT; 576 classroom
• S-9 Limited Heating Cooling: 6,000 + 4,000 = 10,000 OJT; 576 classroom
• D-1 Limited Warm Air, Air Conditioning and Refrigeration: 4,000 + 4,000 = 8,000 OJT; 432 classroom
• D-3 Limited Cooling and Refrigeration: 4,000 + 4,000 = 8,000 OJT; 396 classroom
• B-1 Limited Gas and Oil Burner: 2,000 + 4,000 = 6,000 OJT; 288 classroom
• B-3 Limited Gas and Oil: 4,000 + 4,000 = 8,000 OJT; 360 classroom
• SM-1 Sheet Metal: 8,000 + 4,000 = 12,000 OJT; 576 classroom
• SM-3 Limited Sheet Metal, Residential/Light Commercial: 4,000 + 4,000 = 8,000 OJT; 288 classroom
• SM-5 Limited Sheet Metal Hood Systems: 2,000 + 4,000 = 6,000 OJT; 144 classroom
• ST-1 Solar Thermal: 4,000 + 4,000 = 8,000 OJT; 288 classroom
• G-1, G-9, MT-1, VT-1, HPG-1 and PP-1 are trainee license types with their own separate requirements published by DCP.

Now compare the two rows that matter to most residential HVAC companies. D-1 requires 432 classroom hours and 8,000 OJT hours. S-1 requires 576 classroom hours and 12,000. That is 144 additional classroom hours and 4,000 additional field hours, realistically two more years, for scope a lot of firms will never use. Conversely, if you touch oil burners at all, D-1 is not enough and no amount of experience changes that.

Choose the license by the work you actually sell, not by the biggest number on the list.

The classroom rule and the documentation trap

DCP is explicit and unforgiving on both:

• "Classroom hours are required. On the job training and work experience will not be considered in lieu of the classroom requirement."
• Coursework must match Exhibit A, Required Courses for Heating, Cooling and Sheet Metal, Hearth Product and Fuel Gas License Types in both hours and curriculum content.
• Continuing education certificates and manufacturer certificates do not meet the criteria and will not be considered. The factory training your OEM rep put you through does not count.
• Experience is proven by notarized letters from current or previous employers stating dates of employment and a specific, detailed description of the work. "Letters MUST be notarized."
• "Payroll records, W-2's, or tax returns will not be accepted."

Add two administrative facts: "The Department does not pre-approve or review applications before submission," and "APPLICATION FEES ARE NONREFUNDABLE." There is no informal check. You submit once, and a documentation gap costs you the fee and the calendar time.

The exam

DCP contracts construction-trade examinations to PSI Services LLC. Per PSI's current Connecticut Candidate Information Bulletin for DCP occupational licensure:

• Journeyperson candidates pass a trade portion only. Contractor candidates pass a trade portion and a business and law portion.
• Passing score is 70% on every portion.
• Business and Law: 50 questions, 2 hours, open book, with the Contractors Guide to Business, Law and Project Management, Connecticut, 6th Edition (NASCLA) permitted in the room.
• $59 per examination portion, paid to PSI, first attempt or retake, non-refundable and non-transferable.
• Eligibility is valid one year from State approval of your application.
• For contractors, a passed portion is good for two years. If you later add a second contractor license and have not passed the business portion within two years, you retake it alongside the new trade portion.

Connecticut test centers are in West Hartford and Milford, with nearby Massachusetts sites available.

Fees and the renewal date you are probably about to miss

From DCP's Heating, Cooling and Sheet Metal Work page:

• Application fee, contractor: $150.00 (non-refundable)
• Application fee, journeyperson: $90.00 (non-refundable)
• Renewal fee, contractor: $150.00
• Renewal fee, journeyperson: $120.00
• All heating, cooling and sheet metal work licenses expire annually on August 31.
• Exam fees are separate and paid to PSI at registration.

That August 31 date is worth a calendar entry right now. And note the mismatch: Connecticut's plumbing licenses expire October 31, two months later. Mechanical firms holding both families are managing two annual deadlines, and letting either lapse takes capability off the board. DCP publishes separate reinstatement and reapplication paths, plus continuing education requirements, check both well before the deadline rather than after.

Who holds the license for an HVAC company in Connecticut?

Nobody, if by "who" you mean the company. Connecticut does not issue an HVAC license to a business entity. DCP repeats the same line on the heating page that it uses on the plumbing page: only individuals can apply, company applications are not accepted.

An HVAC business in Connecticut operates on the strength of the licensed individuals it employs. That is not an inference, it is written into the statute. Journeyperson licenses authorize work only "while in the employ of a contractor licensed for such work." And § 20-341s(2) defines a "mechanical contractor" as a business organization "regularly offering to the public the services of its employees licensed to perform plumbing and piping work or heating, piping and cooling work," excluding businesses that work exclusively on residences of four units or fewer and those employing fewer than ten licensed persons. § 20-341t then requires those firms to hold a certificate of registration before doing or offering such work.

Connecticut, in other words, defines a mechanical contracting company by the licensed people on its payroll. The license is personal. The company's legal capacity is borrowed from its employees, and it goes away when they do.

Residential work adds Home Improvement Contractor registration with DCP on top, which is a business registration and a separate obligation from the individual trade license.

The registration side: what your company needs beyond the trade license

The trade license above is a person credential. Separately, Connecticut requires business registrations depending on what market you serve, and the two systems are easy to confuse.

There is no Connecticut general contractor license. DCP instead runs three registrations — Home Improvement Contractor (work on existing residential property, expires March 31), New Home Construction Contractor (building or selling a new home before occupancy, also March 31), and Major Contractor (structural work on threshold buildings over four stories, 60 feet, 150,000 square feet, a 150-foot clear span or 1,000 occupancy — expires June 30 and requires two credit references). Every one of them explicitly excludes "work that is covered under the scope of a trade license," which is exactly the work this page is about.

If you are building the business rather than the credential, read Connecticut general contractor license: there isn't one, there are three registrations alongside this guide. Together they cover both halves of a Connecticut mechanical company's compliance.

What this means if you are building or expanding an HVAC business here

If you own an HVAC company and are not personally licensed in the right Connecticut code, your options are the same three every state produces:

1. Qualify yourself. Verified Exhibit A classroom hours, the OJT structure above including two licensed journeyperson years, notarized documentation, and both PSI portions.
2. Subcontract the licensed work and give up the margin and the schedule control.
3. Employ a licensed contractor-level individual as your qualifier. The license stays with the person; the person works for you; the company can sell and self-perform.

That third path is what a qualifying agent does, and the HVAC qualifying agent role exists in nearly every state under a different name, Connecticut simply calls it employment. Whether that person must be an owner or can be a straight employee varies by state, and we compare the statutory language across states in our guide to the qualifier as owner versus employee.

The line that matters legally is between employing a licensed person and renting a license number. Connecticut's statutes describe employment, "in the employ of," "its employees licensed", and states have been escalating penalties for the alternative. See is it legal to rent a contractor license. Every qualifier we place is a full-time W-2 employee of the client company. There is no percentage arrangement, no per-project fee, no 1099 version, because none of those describe employment and none of them hold up under scrutiny.

Frequently asked questions

Which Connecticut HVAC license do I need? Start from the equipment, not the license. If you install and service warm air, AC and refrigeration but never touch oil burners: D-1. If you touch oil burners at domestic and light-commercial sizes: B-1 (or B-3 for any size). If you do heating and cooling in buildings under three stories within the load limits: S-9. Commercial refrigeration without gas: D-3. Everything, without limits: S-1. Read DCP's published scope statements before you file, working outside your scope is a violation, not a gray area.

How much does a Connecticut HVAC license cost? The state-side figures are fixed and public: $150 contractor or $90 journeyperson application, $59 per PSI portion, then $150 or $120 annually. Everything meaningful sits outside those numbers, the classroom hours you still owe, the notarized documentation, and the years. If what you are really asking is what it costs to get a company legally able to sell HVAC work in Connecticut, that depends on your trade mix, target states, volume and risk. Start with our consultation packages.

Does an EPA 608 certification let me work as an HVAC contractor in Connecticut? No. EPA Section 608 is a federal refrigerant-handling certification and is not a Connecticut license. You need the appropriate state credential to perform the work. We break down the difference in EPA 608 certification vs an HVAC license.

Can my LLC hold a Connecticut HVAC license? No. Only individuals may apply. Your company performs the work through licensed employees, and, if it is a commercial firm with ten or more licensed persons, registers as a mechanical contractor under Chapter 393b.

Do I need a separate sheet metal license for ductwork? Not for ductwork within the limits of the license you already hold. Each limited license in this family "shall include sheet metal work as it pertains to the limitations of this credential." Standalone SM-1, SM-3 and SM-5 licenses exist for sheet metal work outside those limits.

Do I also need a contractor registration? Probably. The trade license covers the mechanical work; a DCP business registration covers the market. Residential remodel work needs Home Improvement Contractor registration, new-home work needs New Home Construction Contractor registration, and structural work on threshold buildings needs Major Contractor registration. See the three Connecticut contractor registrations explained.

What happens if my licensed employee resigns? Your company's authority to perform that work leaves with them, immediately. Plan for it before it happens, see our contractor qualifier contingency plan.

Before you file

Every license code, scope statement, hour figure, fee and renewal date above was verified against the Connecticut Department of Consumer Protection's published licensing and scope-of-work pages, the Connecticut General Statutes (Chapter 393 and Chapter 393b), and PSI's current Connecticut Candidate Information Bulletin, as of August 2026. These are set by the Department, the legislature and the testing vendor and are subject to change. Confirm current requirements and amounts with DCP at DCP.OccupationalProfessional@ct.gov and with PSI before filing or paying.

If the real question is how your company sells HVAC work in Connecticut without spending years qualifying, that is what we do. See hire a qualifying agent, the state licensing guides, or the Connecticut contractor licensing overview. Licensed Connecticut contractors interested in the other side of this can read about becoming a qualifying agent.