CT HVAC license: what your HIC registration doesn't cover, who needs the S-1 or D-1, and your first 30 days

Published November 3, 2026 · Rules checked November 3, 2026

• Free. The full 30-day checklist is on this page. The printable version (PDF, Word or Google Docs) comes by email.
• Deepsel is our product: free estimate, invoice and scheduling software for contractors (scheduling, quotes, invoicing, card payments). The section before the FAQ says where it fits and where it doesn't.
• Not legal advice. Every rule here links to the statute, regulation or agency page it comes from. Ask the Department of Consumer Protection or a Connecticut attorney before you bet a job on my reading.

Connecticut licenses HVAC work person by person, and your home improvement registration doesn't cover any of it. Heating, cooling and ductwork have to be done by someone holding a license from the Department of Consumer Protection's (DCP) heating, piping, cooling and sheet metal board: an S-1 for all of it, or a limited license such as the D-1 (warm air, air conditioning and refrigeration) or the S-9 (hot water and steam heat, plus cooling up to 35 tons, in buildings of up to three stories).^1,3 You don't need the license to own the company. The company does need a licensed contractor on its payroll full time, because only that person can pull the permits, and their license number goes on every truck, ad, bid, contract and invoice.^1,4 The license comes with no bond and no insurance minimum.

Your registration is filed under plumbing, heating and air conditioning. That usually means one of two things: you hold a trade license and registered anyway, or you're building a company that will need someone who does. Both cases are below: who in the business must hold what, what each license covers on a house, what your registration still does for you, permits, a "can I take this job?" table, what crossing the line costs, and a 30-day checklist you can print.

Who in your business must hold the CT HVAC license

"Only individuals can apply, company applications are not accepted," DCP says on its license page.⁵ There's no company license and no ownership share to meet. The statute puts it in one sentence: nothing requires "that the ownership or control of a business" be held by a licensed person, "but all the work and services ... shall be performed by persons licensed for such work."¹ So a non-licensed owner can run an HVAC company. What the company can't do without is a contractor-level licensee, and the regulations explain why.

• Only a licensed contractor pulls the permit. "Licensed contractors alone shall be permitted to acquire building permits" for this work, and to apply, "a contractor shall be directly employed by the business on a regular and full time basis." Signing the application is an attestation that the contractor "is responsible for and will directly supervise the work," and the permit holder is "deemed to have caused or directed the performance of all work performed under the building permit."⁴
• Journeypersons work for a contractor. An S-2, D-2 or other journeyperson who works "without being in the direct and regular employ of a properly licensed contractor" faces discipline, and no journeyperson may go "beyond the limitations of the license held by the contractor for whom he is employed."⁴ If you hold an S-2 yourself, you can't take your own customers until you pass the contractor exam.
• The contractor of record answers for everyone. Invoices for work on a house must name "the licensed contractor of record for such business," who "is liable for the work of any individual who performs work on such contractor's behalf."¹
• One company at a time, in practice. I found no rule that says "one company" in those words. The full-time employment rule does the same job for any work that needs a permit.⁴
• No grace period if they leave. I found none. The day your only contractor-level licensee walks out, nobody at the company can pull a permit and your journeypersons have no licensed contractor to work under. Plan for it before it happens.
• A license can't be lent. No license "shall be transferred to or used by any person other than the person to whom the license was issued."¹ A contractor who stops offering services to the public must also surrender the contractor license within 30 days, or DCP's board can revoke it.⁴

Being someone else's contractor of record

Someone will ask you to stand behind their company. One owner described how he started: "Was already doing sub work before I quit my day job 'under someone else's license'" (r/HVAC). In Connecticut, standing behind a company means being its full-time employee, signing its permits as the person who will directly supervise the work, being deemed to have directed everything done under them, and being named on its invoices as liable for everyone's work.^1,4 A license-for-a-fee deal where you never see the jobs fails the full-time and supervision tests on paper, and your license is the one DCP can suspend. What to ask before you say yes is a separate article.

What your home improvement registration does and doesn't do

Connecticut's Home Improvement Act doesn't apply to anyone holding a trade license "provided such person engages only in that work for which such person is licensed."⁸ DCP's registration page says the same thing from the other side: home improvement does not include "Work that is covered under the scope of a trade license."⁹ In 2003 the Appellate Court applied that exemption to a company. The company's owner, a manager and employees held heating and plumbing contractor licenses, and the court held that "a licensed contractor who was responsible for the services provided on the premises" was enough.¹⁰

So for the furnace, the condenser and the ductwork, your registration does nothing for you and nothing against you. It earns its keep on the rest:

• Work outside your license. Carpentry and drywall around a new duct run sold as its own job, insulation, a remodel you sell with the system. Registered contractors may also do kitchen and bath exhaust, dryer vents, radon vents and stand-alone wood and pellet stoves in homes of up to six units without a sheet metal license.²
• Selling while you line up a licensee. A registered company can sell home improvement work and sub the licensed parts to a licensed contractor. My CT home improvement license article covers that route. Advertising "heating and air conditioning" is another matter: the license law counts "offering to perform such work in any print, electronic, television or radio advertising or listing" as practicing it.¹ An ad for HVAC service with no licensee behind it is unlicensed practice before any job happens.
• Gas fireplaces aren't in it. A home improvement contractor may not do gas hearth work without a gas hearth installer license.⁸

If you keep the registration, it costs $220 a year, needs $20,000 of liability insurance, expires every March 31, and its number goes in your ads.^8,9 That $20,000 is the only insurance floor in Connecticut law that touches an HVAC company, and only through the registration.

CT HVAC license types: S-1, S-2, D-1, D-2, S-9 and the rest

Each contractor license (odd number) has a journeyperson twin (even number) with the same scope that works only for a licensed contractor. The scopes below are from the regulation, RCSA 20-332-5, as amended February 4, 2026.³ The hours are DCP's equivalent-experience route to the contractor exam; the normal route is two years as a licensed journeyperson.⁷

Three things the license guides get wrong or skip:

• Heating licenses include the ductwork for their own scope. Any heating, piping and cooling licensee "may perform 'sheet metal work' as it pertains to the type of license that such person holds."³ The separate SM licenses are for shops that only do ductwork. The B-1 is a burner license, not a sheet metal one.
• There's no S-5 or S-6 any more. They appear in the statute's 1984 solar provisions, but not in the current regulation, and license categories the regulation doesn't define "shall be renewable but no longer available to new applicants."^1,4
• The regulation and DCP's website don't match. DCP's scope page describes the S-7 as covering "heating systems, warm air, boilers," says gas piping and gas appliances "are included within" the D-1, and describes the S-9 as "heating systems, boilers" plus cooling.⁶ The regulation's S-7 and S-9 say "hot water or steam heating systems," with no warm air, and its D-1 doesn't mention gas at all.³ If your licensed contractor holds an S-9 and you plan to sell gas furnaces, or a D-1 and you plan to run gas to them, get DCP's answer in writing first.

What the license costs, and when it renews

The application fee is $150 for a contractor license and $90 for a journeyperson, nonrefundable. After you pass, the license fee is $150 or $120. The exam vendor charges its own fee.^1,5 "All heating, cooling and sheet metal work licenses expire on annually on August 31st," at the same $150 or $120 to renew.⁵ The statute lets the board renew an application that arrives up to a month late, bars any work after expiry until you've applied, and makes you requalify after two years lapsed.¹ I found no continuing education requirement: the statute sets one for electricians and plumbers and none for heating licenses.¹ There's no reciprocity either. "Connecticut does not have reciprocal agreements with any other jurisdiction," though DCP has an application route for an equivalent out-of-state license.⁵ And before a contractor license issues, you show DCP you'll comply with "all state requirements pertaining to workers' compensation and unemployment insurance."¹

What your CT HVAC license covers on a house

The statute defines heating, piping and cooling work as installing, repairing, replacing, maintaining, inspecting, testing or altering "any apparatus for piping, appliances, devices or accessories for heating systems, including sheet metal work," plus "air conditioning and refrigeration systems, boilers," steam piping and pumps.¹ Here's how that lands on the jobs a new company sees first.

• Gas piping to the appliance. Gas piping is also plumbing work in the statute, so plumbers (P-1) and G-1 gas licensees do it too.^1,3 For your side, the S-3, S-7 and S-9 name gas piping for the work they cover, the S-1 covers all heating piping, and DCP's page puts gas piping in the D-1.^3,6 On new gas service the utility has its own step: Eversource won't set a meter until the new piping passes a pressure test "approved by a City/Town inspector," the equipment is hooked to permanent power, and thermostats on gas heat are "installed and operational."²⁰ Southern Connecticut Gas works the same way.²⁰ Eversource's sheet asks for "a licensed plumber," so if your licensed contractor holds an S or G license, call the utility before the first meter set.
• Oil burners. The S-1, S-3, S-7 and S-9 cover them (the S-7 and S-9 up to 5 gallons an hour), and so do the B licenses. The D-1 doesn't, at any size.³ That matters in Connecticut. A Connecticut tech about to go out on his own described his book of side work as "about 70 oil burners I've been taking care of" (r/HVAC). On a D-1, none of those are yours.
• Boilers and hydronic heat. S-1, S-3, S-7 and S-9, within their size limits.³ The tie-in to the house's drinking water for the boiler fill is a different story: plumbing work includes "making connections to back flow prevention devices" and "all water systems for human usage."¹ As I read it, the fill line up to the backflow preventer is the plumber's, and the rest is yours. The same goes for a humidifier's water supply.
• Ductwork. Covered for the system your license covers, as above. A duct-only shop is the case for an SM-3.³
• Mini-splits. Air conditioning and refrigeration, so S-1 and D-1, and the S-9 within 35 tons.³ The new circuit and disconnect are electrical work. More on that two bullets down.
• Condensate. I found no Connecticut rule that names it. My reading: running it to an existing floor drain, sump or condensate pump is part of the equipment you install; cutting into the house's drain piping is plumbing.
• The line voltage circuit and the disconnect. Electrical work covers "any wire, cable ... appliance, apparatus, fixture or equipment" that uses electricity, with no exception for HVAC.¹ A new circuit, breaker or disconnect goes to a licensed electrician. What you may do is work "incidentally, directly and immediately appropriate" to your trade "where such work commences at an outlet receptacle or connection previously installed by a person holding the proper license."^4,2 As I read it, that covers connecting a new condenser from the existing disconnect. It doesn't cover the disconnect.
• Thermostat and control wiring. I found no Connecticut rule that names it, and the statute's electrical definition carves out only lawn sprinkler wiring. Swapping a thermostat for an equivalent one fits the regulation's definition of incidental work: replacing "existing equipment ... with equivalent materials."⁴ For new control wire runs or zoning, ask DCP in writing before you count on your heating license.

Federal rules every Connecticut HVAC company meets

EPA Section 608. Anyone who maintains, services, repairs or disposes of equipment that could release refrigerant "must be certified," and "any person servicing, installing or disposing of stationary appliances ... must be a section 608 certified technician."¹² The supply house checks: a company can buy refrigerant by showing it employs a certified tech, with "a copy of the certification card and a list of those authorized to buy." Cards don't expire. Apprentices are exempt only while "closely and continually supervised by a certified technician."¹²

A2L refrigerants (R-454B, R-32). EPA's listings for these "require compliance with UL Standard 60335-2-40 Edition 3."¹³ Connecticut's 2022 building code, still in force, added the 2019 edition of UL/CSA 60335-2-40 as an accepted listing for heat pumps and other equipment in both the residential code and the mechanical code, its refrigeration chapter included.¹¹ The 2026 codes, which are to adopt the 2024 International Mechanical and Residential Codes, "were expected to take effect on July 1, 2026," but "the effective date has been delayed."¹¹ I read no other Connecticut notice on A2L, so ask the building official how they want A2L equipment documented before your first install. And EPA's rule effective July 27, 2026 "allows the inventory of residential and light commercial air conditioning and heat pump equipment that was manufactured in the United States or imported into the United States before January 1, 2025, to continue to be installed."¹³

Lead paint. Connecticut doesn't run its own renovation program, so EPA enforces its rule here directly. Cutting into walls or ceilings for duct runs or registers in a house built before 1978 needs an EPA-certified firm once you disturb more than 6 square feet of paint in a room (20 outside), and EPA says that covers "all firms, even sole proprietorships."¹⁴ Old boiler and pipe insulation is the other trap: more than 3 square or linear feet of asbestos needs a licensed asbestos contractor, homes included.¹⁵

Apprentices, journeypersons and helpers

An apprentice in Connecticut is someone registered with the Labor Department, and you request that registration before the apprentice starts.⁴ Apprentices work only "in the presence and under the direct supervision" of a licensed contractor or journeyperson, meaning "within the sight and/or hearing of said licensed person." Whoever pulled the permit is deemed to have allowed any unsupervised work.⁴ The hiring ratio counts licensees (contractors and journeypersons) against apprentices:²

• 1 licensee: 1 apprentice. 2: 2. 3: 3.
• 6 licensees for 4 apprentices, 9 for 5, 12 for 6, then 3 more licensees for each added apprentice up to 24 for 10, and 3 to 1 after that.
• Since 2025 a contractor with eight or fewer licensees can apply for ratio relief up to one apprentice per licensee, and DCP has to answer within ten business days. The conditions: no Labor Department enforcement against you in three years, at least one apprentice in a program at one of the state's technical education and career schools (or a good-faith try to find one), and a signed statement of undue hardship.²

Journeypersons may work alone, but only as employees of a licensed contractor and only inside that contractor's license.⁴ There's no registration for a "helper." Anyone doing licensed work is either licensed or a registered apprentice under direct supervision. Wilfully employing someone without a license for the work is the same offense as doing it yourself.² A helper who carries equipment and cleans up isn't doing licensed work. One who brazes the line set is.

Where your CT HVAC license stops

• New circuits, disconnects and panel work: an electrician.¹
• Plumbing tie-ins: the drinking water connection for a boiler fill or humidifier, and any cut into the house's drain piping, as I read the plumbing definition.¹
• Gas lines to things that aren't heating or cooling equipment, like a generator, a range or a pool heater. The G-1 covers "gas piping systems and approved gas appliances" outright, and plumbers do gas piping.^3,1 Whether an S-1 covers a generator line, I couldn't settle from the text. Sub it to a G-1 or P-1, or ask DCP.
• Gas fireplaces, inserts and log sets: the HPG gas hearth licenses.³
• Oil burners on a D-1, and anything past the S-7 or S-9 limits: buildings over three stories, heating loads over 500,000 BTU, cooling over 35 tons a system.³
• Building work sold as its own job: your home improvement registration, not your license.⁸
• Asbestos removal over 3 square or linear feet.¹⁵

Permits and inspection in Connecticut

Connecticut has one building code for the whole state, enforced by each town's building official. The 2022 Connecticut State Building Code is still in force while the 2026 code waits on the legislature's regulation review committee.¹¹

• A change-out needs a permit. The code requires one to "replace any electrical, gas, mechanical or plumbing system." The mechanical exemptions are portable appliances, piping inside the equipment, "Replacement of any minor part that does not alter approval of equipment," and self-contained refrigeration holding 10 pounds of refrigerant or less.¹¹ A like-for-like condenser or furnace swap isn't on that list. A capacitor or an igniter is.
• Your licensed contractor pulls it. In person, by an original signed letter on your letterhead naming the town, the job, the start date and "the license numbers of all contractors to be involved in the work," or through a town's online application.¹ No licensee may start until "each applicable permit ... has been obtained."¹
• The town inspects, and on a permitted job the building official can ask anyone for proof of licensure and order an unlicensed worker to "cease work at the site immediately."¹⁸
• The homeowner exemption is narrow. It covers people working on a single-family house they own and live in, "subject to inspection and approval by the building official."² A customer who pulls a homeowner permit and hires you has the wrong permit for the job.
• Towns can't add a license. A state licensee may work "in any town or municipality of this state without further examination or licensing by any town or municipality."¹ New Haven's permit checklist, for one, asks for "A copy of your non-expired state issued contractor license."¹⁹ I didn't check all 169 towns, so ask each building department how it takes applications the first time you work there.

The HVAC installation checklist has a close-out section that keeps the permit and the inspection sign-off with the job.

Can I take this job? A table for Connecticut HVAC contractors

The verdicts assume your company's licensed contractor holds an S-1 and works for you full time. Where a D-1 or S-9 changes the answer, the row says so. "Yes, with a permit" means your licensed contractor pulls it before work starts.

What happens if you cross the line in CT

• Unlicensed work, hiring someone unlicensed for it, or advertising it. Doing any of these wilfully is a class B misdemeanor, but charges need DCP's written finding that the work required a license first.² That carries up to six months in jail and a $1,000 fine.¹⁶ Separately, DCP or the board can impose a civil penalty of up to $3,000 per violation, and every violation of the chapter is an unfair trade practice the customer can sue over, with punitive damages and attorney's fees possible.^2,17
• Stop work orders. Since 2025 DCP can issue a notice of violation for unlicensed work, ratio violations, unregistered apprentices or "failure to obtain a permit," then a stop work order, then a fine of up to $500 per violation per day for ignoring it.² When a building official reports the violation, half of any civil penalty goes to that town.²
• Working past August 31. Working after your license expires is listed with unlicensed work, same penalties.²
• No number on the truck or the invoice. Up to $500 per violation, with no fine for the first one.¹
• The license itself. DCP and the board can suspend or revoke a license for violating the regulations, and a licensee who does work in violation of any state or town code "or who violates generally accepted basic trade practices" faces discipline.^1,4

Can you still collect?

I found no Connecticut statute or case that says in so many words that an unlicensed HVAC contractor can't be paid. Two rules come close. A written contract for work on a house by a licensed contractor, or by a business doing licensed work through licensed people, isn't "valid or enforceable against an owner" unless it contains, among other things, "the name and license number of any licensees performing the work."¹ A job done by unlicensed people can't truthfully meet that. And a company with no licensee loses the Home Improvement Act exemption, so its house jobs fall under that act's contract rules: nine required items, and no enforceable contract at all without a current registration.⁸ Add the customer's unfair trade practice claim and the risk runs well past one unpaid invoice.

Insurance: no Connecticut rule I found voids a policy for work outside the license. That's in your policy's exclusions, so ask your agent in writing. One owner's start-up estimate puts the cost in perspective: "You could probably start with about $2k in tools, and a $300/mo insurance policy plus licensing" (r/HVAC). It's a cheap policy to lose on a technicality.

Your first 30 days: the CT HVAC license checklist

This is the whole list. The printable version has the same items with blanks for your license, registration, permit and policy numbers, your EPA 608 cards and your renewal dates: make your own copy in Google Docs, download the Word version (.docx), or download the PDF. Pick a format, enter your email and I'll send the links.

The business

• ☐ Entity. Form the LLC or corporation with the Secretary of the State, or decide to run as a sole proprietor. If you do business under a name other than the one on your license application, the board wants 10 days' notice first.⁴
• ☐ Sales and Use Tax Permit from the Department of Revenue Services, before you provide any services: "All contractors, including subcontractors, must obtain" one.²¹
• ☐ Know which jobs are taxable. Repairs, maintenance, tune-ups and diagnostic charges on furnaces, oil burners and AC units are taxable even in an owner-occupied home. Installing a system in an owner-occupied one- to three-family house or new construction isn't taxable on your labor, and you pay the tax on the equipment and materials you buy. In commercial buildings and rentals, your labor is taxable too.²¹

The license and your contractor of record

• ☐ Look everyone up on eLicense: your contractor-level licensee and every journeyperson, with the license type and the August 31 expiry.⁵
• ☐ Contractor of record named. An S-1, D-1, S-9 or other contractor licensee employed full time, whose license covers every kind of job you'll sell. Check the D-1's oil burner gap and the S-9's limits against your service area.^4,3
• ☐ Workers' compensation and unemployment compliance shown to DCP for the contractor license.¹
• ☐ A plan if your licensee leaves, because I found no grace period. Who else holds a contractor license you could hire?

Your home improvement registration (if you keep it)

• ☐ Current on eLicense, with the registrant matching your company (an individual registration doesn't cover an LLC). It expires March 31 every year, at $220.^9,8
• ☐ $20,000 of general liability insurance on file, and the registration number in your ads.^8,9

Insurance and employees

• ☐ General liability. The license law sets no minimum. Carry it anyway: general contractors, property managers and commercial customers ask for the certificate.
• ☐ Workers' compensation before the first employee starts. "With few exceptions, all employers in the State of Connecticut are required to have workers' compensation insurance." Sole proprietors are covered only if they opt in; LLC members and corporate officers may elect out.²²
• ☐ Unemployment insurance registration with the Labor Department: "All employers of one or more persons (full or part-time) must register online."²²

Your number on everything

• ☐ Trucks: the state license number on every commercial vehicle, "at least one inch high and legible."^4,1 Add the registration number if you're registered.
• ☐ Ads, website, listings and cards: the license number "in a conspicuous manner."¹
• ☐ Bids, contracts, invoices and letterhead: the same.¹ The HVAC invoice template has a place for it.

Contracts and invoices for house jobs

• ☐ Contract form signed by the owner and you, with the whole agreement, the date, your company's owner name, address and phone, "the name and license number of any licensees performing the work," the three-day cancellation notice, and start and completion dates. For an emergency repair, the owner can waive cancellation in a signed, dated statement.¹ The CT contract article has the cancellation notice text.
• ☐ Invoice or work order showing the contractor of record's full legal name and license number, your address and phone, the work, "the labor and material costs," the dates, and "the complete name of each licensee who performed such work."¹

Permits, towns and the gas company

• ☐ Who signs permits: your licensed contractor, or an agent carrying an original signed letter for each job. Find out which towns you work in take online applications.¹
• ☐ Permit for every change-out, issued before work starts.^11,1
• ☐ Gas utility: how Eversource or Southern Connecticut Gas wants new piping tested and the meter set in your area.²⁰

People

• ☐ Nobody unlicensed on licensed work. Apprentices registered with the Labor Department before they start, inside the ratio, always within sight or hearing of a licensee.^4,2
• ☐ EPA 608 cards for everyone who touches refrigerant, with copies on file for the supply house.¹²
• ☐ Subs lined up and looked up: an electrician for circuits and disconnects, a plumber or G-1 for water and non-heating gas lines.^1,3
• ☐ Pre-1978 houses: firm EPA lead-safe certified before you cut into painted walls or ceilings.¹⁴

Renewal

• ☐ August 31, every year: every heating, cooling and sheet metal license, $150 for a contractor and $120 for a journeyperson. Not getting the notice doesn't excuse a late renewal.^5,4
• ☐ March 31, every year: the home improvement registration, if you keep it.⁸
• ☐ Continuing education: none required for heating licenses that I found. Keep watching for the 2026 building code's effective date.^1,11

More for new HVAC contractors

• HVAC pricing guide: what to charge for a service call, your labor rate and the first jobs, with a free rate sheet.
• HVAC tune-up checklist: the visit in order, the target readings and what to charge, with a free report card.
• Opening a supply house account: what to bring, cash or credit, and how dealer programs work, with a free checklist.
• Quoting your first system replacement: the price, the scope and what the quote must include, with a free proposal template.
• Starting an HVAC business while still employed: side work, your boss's customers, non-competes and when to go.
• Register every install: maker deadlines, your labor warranty and what a callback costs, with a free close-out sheet.
• Your first slow season: the customer list and the one reminder that fills a calendar, with a free log.

Where Deepsel fits

Deepsel is the field service software I build, and for this topic it handles the paperwork side, not the law. It has no license, permit, renewal or insurance tracking, and it won't stop you quoting an oil burner on a D-1. What it does: the shop-wide quote terms you set once are copied onto every new quote, and the invoice footer onto every new invoice, so your contractor of record's name and license number (and your registration number, if you have one) reach the customer every time. Invoice lines show the visit date they came from, and service and material lines are separate items, so labor and materials show up separately the way Connecticut wants on a house invoice. It doesn't print which tech did the work, so add the licensee's name to the line or the footer. Customers approve and sign quotes on screen, and equipment records keep the type, brand, model, serial, year, filter size, tonnage, refrigerant, SEER2 or AFUE, and a nameplate photo for the next call. It's free up to 30 estimates and 30 invoices a month, with scheduling and dispatch, quotes, invoicing, card payments, and customer and equipment records; Pro is $29 a month with unlimited estimates and invoices (see pricing).

Frequently asked questions

Do you need a license to do HVAC work in CT?

Yes, at any job size. Connecticut's trade licensing law has no small-job exemption, and offering the work in an ad counts as doing it. The license belongs to a person, not a company: an S-1 covers all heating, piping and cooling work, and limited licenses such as the D-1 (warm air, air conditioning and refrigeration), S-9 (hot water and steam heat plus cooling up to 35 tons, buildings of up to three stories) and B-1 (gas and oil burners) cover parts of it. The exceptions are narrow: homeowners working on the single-family house they own and live in, still subject to inspection, and a few others such as utility and government employees.

What is an S-1 license in CT?

The S-1 is Connecticut's unlimited heating, piping and cooling contractor license. Its holder 'may do all heating, piping and cooling work' as the statute defines it, sheet metal included, with no building size or tonnage limit. To sit the exam you need two years as a licensed journeyperson (usually an S-2), or DCP's equivalent route of 12,000 hours of on-the-job training and 576 classroom hours. The application fee is $150, the license fee after you pass is $150, and it renews every August 31 for $150.

What is the difference between an S-2 and a D-2 license in CT?

Both are journeyperson licenses, so both holders may work only while employed by a licensed contractor. The S-2 is unlimited: all heating, piping and cooling work. The D-2 is limited to warm air, air conditioning and refrigeration systems and the piping that carries heating or cooling media, and it excludes oil burners of any size. The contractor versions are the S-1 and the D-1. A journeyperson also can't go past the limits of the license their employer holds.

What is a B2 license in CT?

The B-2 is the limited gas and oil burner journeyperson license. It covers installing, servicing and repairing gas or oil burners in domestic and light commercial installations, defined as burners using five gallons an hour or less, and only while employed by a licensed contractor. The B-1 is the contractor version, and the B-3 and B-4 cover burners of any size. The B licenses aren't sheet metal or ductwork licenses.

Can I own an HVAC company in CT without a license?

Yes. The statute says ownership of the business needn't be held by a licensed person, but all the licensed work has to be done by licensed people. In practice the company needs a contractor-level licensee (S-1, D-1, S-9 or similar) employed full time, because only licensed contractors may pull permits for this work, and journeypersons may work only for a licensed contractor. That person's name and license number go on the company's invoices as the licensed contractor of record.

How much does a CT HVAC license cost?

The application fee is $150 for a contractor license and $90 for a journeyperson license, both nonrefundable. After you pass, the initial license fee is $150 for a contractor and $120 for a journeyperson. The exam vendor charges its own fees. Every heating, cooling and sheet metal license expires on August 31 each year and renews for the same $150 or $120. I found no continuing education requirement for these licenses.

How do I look up a CT HVAC license?

Use DCP's eLicense site (elicense.ct.gov), the same system you apply and renew through. Search by name or license number and check the license type, because the type sets the scope: a D-1 can't touch an oil burner and an S-9 is capped at three stories and 35 tons. Look yourself and every tech up before the first job, and check subcontractors the same way.

Does Connecticut have HVAC license reciprocity?

No. DCP says plainly: 'Connecticut does not have reciprocal agreements with any other jurisdiction.' What it does have is an application route for an equivalent out-of-state license, and another for equivalent experience and training, where you prove classroom hours and on-the-job hours with notarized letters from employers. DCP won't accept payroll records, W-2s or tax returns as proof. You still take the Connecticut exam.

Does a CT HVAC contractor need a home improvement registration?

Not for the HVAC work. The Home Improvement Act doesn't apply to a licensee doing only the work their license covers, and the Appellate Court has applied that to a company whose licensed contractor was responsible for the job. You need the registration for home improvement work outside your license, such as carpentry, insulation or a remodel you sell along with the system. If you keep it, it expires every March 31 and requires $20,000 of liability insurance.

Do I need a permit to replace a furnace or AC unit in CT?

Yes. Connecticut's building code requires a permit to replace any mechanical or gas system. Its mechanical exemptions are portable appliances, piping inside the equipment, minor parts that don't change the equipment's approval, and self-contained refrigeration units holding 10 pounds of refrigerant or less. A like-for-like change-out still needs one. On a customer's job only a licensed contractor may pull it, and work can't start until it's issued. The town's building official issues it and inspects.

Sources

1. Conn. Gen. Stat. chapter 393 (revised to January 1, 2025): §20-330 (definitions of contractor, electrical work, plumbing and piping work including gas and connections to backflow preventers, heating, piping and cooling work, sheet metal work), §20-333 (application fees $150 and $90), §20-334 (license required, including offering in advertising; not transferable; license number on commercial vehicles, ads, bid proposals, contracts, invoices and stationery, fine up to $500 per violation after the first), §20-334a (contractor and journeyman licenses; workers' compensation and unemployment insurance evidence; apprentice supervision; S-5 and S-6 named in the 1984 solar provisions), §20-334d (continuing education for electricians and plumbers), §20-335 (license fees $150 and $120, annual expiry, one-month renewal window, requalifying after two years), §20-337 (ownership of businesses), §20-338 (valid in every town without further licensing), §20-338a, §20-338b (who signs permit applications; authorization letter; electronic applications), §20-338c (no work before the permit), §20-338d (contracts for work on a private residence), §20-338e (invoices and work orders; licensed contractor of record). cga.ct.gov, read November 3, 2026.
2. Conn. Gen. Stat. chapter 393, 2026 Supplement: §20-332b (hiring ratios; ratio relief added by P.A. 25-47), §20-340 (exemptions, including (5) household appliances, (11) owner-occupied single-family home, (16) residential sheet metal for home improvement registrants), §20-341 (class B misdemeanor after DCP's written determination; civil penalty up to $3,000 per violation; half to the town on a building official's report; unfair trade practice; incidental work exception; notice of violation, stop work order and fine up to $500 per violation per day). cga.ct.gov, read November 3, 2026.
3. Regulations of Connecticut State Agencies §20-332-5, "Licenses issued by the state board of heating, piping, cooling, and sheet metal work examiners" (amended through February 4, 2026): S-1 to S-10, B-1 to B-4, D-1 to D-4, G-1 and G-2, SM-1 to SM-6, (aa) sheet metal work within each license, HPG-1 and HPG-2. eregulations.ct.gov, read November 3, 2026.
4. Regulations of Connecticut State Agencies: §20-332-1 (definitions, including heating, piping and cooling maintenance, contractor, commercial vehicle, incidental work), §20-332-7a (undefined license categories renewable only; incidental work from a connection installed by a proper licensee), §20-332-13 (renewal), §20-332-15a (apprentices: Labor Department registration before employment, direct supervision "within the sight and/or hearing," ratios), §20-332-16 (only licensed contractors employed "on a regular and full time basis" acquire permits; permit holder deemed to have directed all work; journeypersons in the direct and regular employ of a licensed contractor; no work beyond the employer's license; business name notice; license numbers on commercial vehicles at least one inch high), §20-332-17 (letter of intent; surrender of a contractor license within 30 days of ceasing to offer services). eregulations.ct.gov, read November 3, 2026.
5. Department of Consumer Protection, "Heating, Cooling and Sheet Metal Work, Hearth Product Work, Fuel Gas Work Licenses" ("Only individuals can apply, company applications are not accepted"; "Connecticut does not have reciprocal agreements with any other jurisdiction"; exam vendor fees; application fees; licenses expire every August 31, renewal $150 and $120). portal.ct.gov, read November 3, 2026.
6. Department of Consumer Protection, "Heating, Piping and Cooling License Types and Scope of Work" (S-7 "heating systems, warm air, boilers"; gas piping "included within" the D-1; S-9 "heating systems, boilers" and cooling to 35 tons), portal.ct.gov; "Sheet Metal Licenses and Scope of Work," portal.ct.gov. Both read November 3, 2026.
7. Department of Consumer Protection, "Heating Contractor - Equivalent Experience and Education" (on-the-job and classroom hours by license type; notarized employer letters; payroll records, W-2s and tax returns not accepted). portal.ct.gov, read November 3, 2026.
8. Conn. Gen. Stat. chapter 400, Home Improvement Act: §20-419 (definitions), §20-420(d) (no gas hearth work without the license), §20-421 ($20,000 general liability), §20-427 (registration number in ads; March 31 expiry), §20-428(4) (the act doesn't apply to a licensee "provided such person engages only in that work for which such person is licensed"), §20-429 (contracts not enforceable against an owner unless entered into by a registered contractor). cga.ct.gov, read November 3, 2026.
9. Department of Consumer Protection, "Home Improvement Contractor" (home improvement does not include "Work that is covered under the scope of a trade license"), portal.ct.gov; "Home Improvement Contractor Application" ($220; "general liability insurance of no less than $20,000"; an individual registration doesn't cover an LLC), portal.ct.gov. Both read November 3, 2026.
10. Santa Fuel, Inc. v. Varga, 77 Conn. App. 474 (2003): the exemption in §20-428(4) applied where "a licensed contractor who was responsible for the services provided on the premises" held heating and plumbing licenses; "That purpose will not be subverted by allowing businesses with a corporate structure that hire licensed plumbers for the performance of their plumbing work to be exempt from the necessity of a written contract." courtlistener.com (scan), read November 3, 2026.
11. 2022 Connecticut State Building Code (with Errata #1), effective October 1, 2022: amendments to the 2021 IRC R105.1 (permit to "replace any electrical, gas, mechanical or plumbing system"), R105.1.1 (contractor applications under §20-338b), R105.2 (work exempt from permit), M1402.1, M1403.1, M1412.1, M1413.1 and the IMC referenced standards (UL/CSA 60335-2-40-2019). portal.ct.gov. Department of Administrative Services, "Building and Fire Code Adoption Process" (2026 codes "were expected to take effect on July 1, 2026 ... the effective date has been delayed"), portal.ct.gov. Both read November 3, 2026.
12. EPA, "Section 608 Technician Certification Requirements" (certification required; credentials don't expire; supervised apprentices exempt), epa.gov; EPA, "Questions and Answers about the Refrigerant Sales Restriction" ("Any person servicing, installing or disposing of stationary appliances ... must be a section 608 certified technician"; buying through an employer with a copy of the card), epa.gov. Both read November 3, 2026.
13. EPA, "Questions and Answers About SNAP" (A2L listings "require compliance with UL Standard 60335-2-40 Edition 3"), epa.gov; 91 FR 31284, May 26, 2026, effective July 27, 2026 (pre-2025 residential and light commercial AC and heat pump inventory may continue to be installed), federalregister.gov. Both read November 3, 2026.
14. EPA, "Lead Renovation, Repair and Painting Program" ("This includes all firms, even sole proprietorships"), epa.gov; 40 CFR 745.83 (minor repair: 6 square feet per room inside, 20 outside), ecfr.gov; Connecticut DPH ("the State of Connecticut is not authorized to administer the EPA's RRP"), portal.ct.gov. All read November 3, 2026.
15. Connecticut DPH, "Asbestos Consultants and Contractors" (more than 3 linear or 3 square feet needs a licensed asbestos contractor). portal.ct.gov, read November 3, 2026.
16. Conn. Gen. Stat. §53a-36 (class B misdemeanor, "a term not to exceed six months") and §53a-42 (fine "not to exceed one thousand dollars"). cga.ct.gov, read November 3, 2026.
17. Connecticut Unfair Trade Practices Act, Conn. Gen. Stat. §42-110g (actual damages, punitive damages at the court's discretion, attorney's fees). cga.ct.gov, read November 3, 2026.
18. Conn. Gen. Stat. §29-261(c) (building official may request proof of licensure and order unlicensed workers to "cease work at the site immediately"). cga.ct.gov, read November 3, 2026.
19. City of New Haven, Office of Building Inspection and Enforcement, "Contractor Info" ("A copy of your non-expired state issued contractor license"). newhavenct.gov, read November 3, 2026.
20. Eversource, "Your new gas service was installed today, what's next" (Connecticut meter set requirements: pressure test by "a licensed plumber," approved by a town inspector; equipment on permanent power; thermostats installed), eversource.com; Southern Connecticut Gas, "Commercial Steps to Convert" (contractor arranges "a pressure test approved by a town official" before the meter is turned on), soconngas.com. Both read November 3, 2026.
21. Department of Revenue Services, Informational Publication 2018(2), "Building Contractors' Guide to Sales and Use Taxes" (sales and use tax permit before providing services; heating and central air conditioning: installation, repair and maintenance rules; owner-occupied residential property of one to three units; diagnostic charges taxable; 6.35%), portal.ct.gov; "Services Subject to Sales and Use Taxes" ("Repair services to electrical or electronic devices including but not limited to air conditioning and refrigeration equipment"), portal.ct.gov. Both read November 3, 2026.
22. Connecticut Workers' Compensation Commission, "About workers' compensation insurance," portal.ct.gov; Connecticut Department of Labor, "How do I register my business for Unemployment Insurance?," portal.ct.gov. Both read November 3, 2026.