Aspiring HVAC technicians in Tennessee and homeowners hiring HVAC services often share a common question: what does it take to be a licensed HVAC contractor in the Volunteer State? In Tennessee, obtaining an HVAC license is a legal requirement for large projects and a mark of professional competence.
This article provides a clear overview of the Tennessee HVAC licensing process, covering both residential and commercial aspects. We’ll explore license classifications (like CMC and CMC-C), the exam process, preparation resources, and why working with a licensed contractor is so important.
By the end, you’ll understand what to expect from the HVAC licensing exams and how licensing protects you, whether you’re an HVAC trainee or a homeowner seeking reliable service.
Why HVAC Licensing Matters in Tennessee
In Tennessee, HVAC contractors must be properly licensed to take on significant jobs. State law mandates a contractor’s license for any heating, ventilation, and air conditioning project that costs $25,000 or more. This license is issued by the Tennessee Board for Licensing Contractors, a state board established to protect public health and safety by ensuring contractors are qualified and accountable.
Practically, this means that if you’re an HVAC professional aiming to bid on large residential or commercial projects, you need to be licensed; and if you’re a homeowner, you should verify that your contractor holds a valid license for jobs of this scale.
For smaller HVAC projects under $25k, a state HVAC license may not be required, but other credentials are – for example, any electrical wiring for an HVAC installation must be done by a licensed electrician. Additionally, many city or county governments in Tennessee require local HVAC or mechanical permits and certifications regardless of project size.
Why does all this matter to homeowners?
A licensed HVAC contractor has demonstrated their knowledge through exams and met stringent requirements for experience, insurance, and even financial stability. Licensing ensures the person or company working on your HVAC system knows what they’re doing and follows state codes. This protects you from shoddy workmanship and potential safety hazards.
In fact, the Tennessee Department of Commerce & Insurance (TDCI) reported over 900 consumer complaints against contractors in 2023, totaling to 44% increase since 2019. Many of these complaints involve unlicensed or unscrupulous operators.
The takeaway for consumers is clear: hiring a licensed HVAC professional greatly reduces the risk of becoming another statistic. Always ask for a contractor’s license number and verify it on the state’s website to ensure they’re in good standing.
For aspiring HVAC technicians, getting licensed is equally critical. It’s not only the law, but it also opens doors in your career. With a Tennessee HVAC license, you can legally pull building permits, bid on projects, advertise your services, and operate an HVAC business independently.
Tennessee HVAC License Classifications: CMC vs. CMC-C
When navigating HVAC licensing in Tennessee, you’ll encounter two key license classifications: CMC and CMC-C. Understanding these will help clarify the scope of work you’re allowed to do with each license.
CMC – Full Mechanical Contractor
A “CMC” license is a full mechanical contractor’s license. It covers the broad spectrum of mechanical systems, including HVAC, refrigeration, plumbing (often categorized as CMC-A for plumbing), and other mechanical work like gas piping and fire sprinklers. In essence, CMC is an all-encompassing license for mechanical contracting.
Obtaining a CMC license typically means you have met qualifications in multiple areas (such as both HVAC and plumbing). In fact, the state requires pre-approval to even sit for the full mechanical (CMC) trade exam – you must demonstrate adequate experience in the mechanical trades, including plumbing, before testing.
This license is useful for contractors who want to handle large commercial HVAC systems that integrate with plumbing or who plan to offer a wider range of mechanical services. However, it’s more involved to get, as you may need to pass more than one trade exam (or a combined exam) or show proof of qualifications in each sub-trade.
CMC-C – HVAC/Refrigeration Contractor
The majority of HVAC contractors in Tennessee pursue the CMC-C license, which is specific to HVAC/R. According to the Tennessee Board for Licensing Contractors, a CMC-C license is required for contractors who “need to pull permits for projects limited to heating, ventilation, and air conditioning.”
In other words, if your work focuses on installing and servicing HVAC and refrigeration systems (including geothermal HVAC equipment and gas piping for heating systems), the CMC-C classification is the one for you. This license allows you to install, repair, and maintain heating and cooling units in both residential and commercial settings.
It’s narrower in scope than the full CMC, but it is the standard license for HVAC professionals. Most heating and air companies in Tennessee hold a CMC-C license unless they also do extensive plumbing or other mechanical work.
In practical terms, both licenses permit work on residential and commercial HVAC systems. There isn’t a separate “residential-only” HVAC license at the state level – instead, the distinction comes from the project size and whether other trades are involved.
If you’re bidding a large commercial HVAC job (say a $500,000 HVAC installation for an office building), you could do so with a CMC-C license as long as it’s purely HVAC work. You would also need a monetary limit on your license high enough to cover the project’s value (Tennessee assigns a monetary limit to each contractor license based on the company’s financial statements)
For most HVAC technicians starting out, the CMC-C license is the target. You can always add classifications later (for example, obtaining a plumbing subclass CMC-A in the future, or upgrading to full CMC) by taking additional exams and applying to the Board.
Tennessee does allow contractors to hold multiple classifications – often, a contractor will carry “CMC-C” for HVAC and perhaps “CMC-A” for plumbing, unless they went straight for the full CMC which inherently covers both. So if you’re a homeowner checking a contractor’s credentials, you might see something like “CMC-C” on their license, denoting they are licensed for HVAC/Refrigeration contracting.
Both CMC and CMC-C licenses require the contractor (or their qualifying agent) to pass the relevant exams and meet experience requirements, which we’ll discuss next.
Exam Requirements and Licensing Process
Getting your Tennessee HVAC contractor’s license is a multi-step process. The exams are a crucial part of it, but there are other requirements to fulfill as well. Here’s an overview of what aspiring contractors need to do:
1. Meet Basic Eligibility (Experience/Education)
Before you can take the licensing exams, you should have a solid foundation of HVAC knowledge and experience. Tennessee does not mandate a specific number of years of experience to take the CMC-C HVAC exam, and you do NOT need prior approval to register for that exam.
This means you can sign up for the HVAC trade test whenever you feel prepared. However, when you eventually apply for the license, the Board will ask about your background in the trade. Typically, applicants should be at least 18 years old and have a combination of education and hands-on experience in HVAC.
Many successful candidates complete an HVAC training program (through a technical college, trade school, or union apprenticeship) and spend a few years working under a licensed HVAC contractor to gain practical experience.
In Tennessee, it’s common for technicians to first earn local journeyman HVAC or electrician credentials in a city/county, then pursue the state contractor license for career advancement. While the state doesn’t require formal classroom hours, the complexity of the exam (as we’ll see) is such that on-the-job experience and study are essential.
If you aim for the full CMC license, note that you must be pre-approved by the Board before taking the mechanical exam – this usually entails showing significant experience in both HVAC and plumbing, given the broader scope.
The bottom line is: come into the exam with a strong foundation of HVACR theory, applicable codes, and practical know-how.
2. Register for the Required Exams
Tennessee HVAC contractors actually have to pass two exams: the Business and Law exam and the HVAC/Refrigeration trade exam (plus a plumbing trade exam if you’re going for full CMC mechanical, but we’ll focus on HVAC). The exam process is managed by PSI Exams, a professional testing service contracted by the state.
According to the Tennessee Board, PSI is the official exam vendor and offers these tests by appointment at various testing centers statewide. You can register online through PSI’s portal or by phone, and exams are typically available in cities like Nashville, Knoxville, Chattanooga, Jackson, Johnson City, and Memphis, among others, so you can choose a convenient location.
When registering, you’ll need to pay an exam fee (currently $55 per exam as of this writing and select your desired date and site. PSI provides a Candidate Information Bulletin that lists all the Tennessee contractor exams, their content outlines, reference materials allowed, and test center policies.
Be sure to download and read that bulletin – it’s basically the rulebook for your exam day.
On exam day, plan to arrive early at the PSI test center with proper ID as required (typically two forms of ID, one being a government-issued photo ID). The testing environment will be proctored and secure: no personal items, no programmable calculators beyond basic functions, and absolutely no sharing of materials. Remember that talking or cheating can lead to immediate disqualification.
The good news is that you get your score immediately after the computer-based test. Once you pass both required exams, you’ll receive a score report that you will include in your license application.
3. Submit Your License Application
Passing the exams is a huge milestone, but you’re not licensed yet. You must compile and submit an application to the Tennessee Board for Licensing Contractors to actually receive your HVAC contractor’s license. The application will ask for detailed information, including:
- your business entity (sole proprietorship, LLC, etc.),
- personal or business financial statements reviewed by a CPA (the Board uses this to set your initial monetary limit on projects)
- proof of general liability insurance and workers’ compensation insurance coverage, and
- personal background disclosures (like any criminal convictions or past license disciplinary actions)
- provide a reference letter attesting to your experience or character in the trade
A $250 application fee is required with submission. The Board meets regularly to review applications; it can take a few weeks (typically 4-6 weeks) for approval, so plan accordingly.
In some cases, the Board might invite you for an interview (especially if there are any red flags in your application, such as a past complaint, or if they want to verify your experience). But if everything is in order – you passed the exams, your paperwork is complete, and you meet the criteria – you’ll be granted your license.
Licenses are issued for two-year periods in Tennessee and must be renewed biennially with a renewal fee (including some continuing education for certain classifications). Once you have that license in hand, you are officially a licensed HVAC contractor in Tennessee!
You can then legally advertise your services, bid jobs over $25k, pull permits statewide (and you won’t have to re-test for local jurisdictions – local governments accept the state license), and call yourself a licensed professional.
Preparing for the HVAC Licensing Exams
Given the breadth of knowledge covered in the Tennessee HVAC exams, thorough preparation is crucial. The good news is there are many resources and strategies to help you succeed on your first attempt:
Study the Reference Materials
Start with the official references listed by PSI for the exam.
- Acquire the latest editions of the International Mechanical Code and International Fuel Gas Code, as these codes drive a lot of the questions.
- Familiarize yourself with ACCA Manual J (for residential load calculations) and any standard HVAC textbooks (like Modern Refrigeration and Air Conditioning).
Don’t just read them—practice looking up answers to hypothetical questions, so you become fast at finding information. Remember, the exam is open-book, but you’ll only have the specific allowed books.
Tip: Tab your books with permanent, labeled tabs for key sections (per PSI rules).
Being comfortable with your references can easily boost your score by allowing you to quickly verify things like duct sizing charts or gas pipe sizing tables during the test.
HVACR Education Resource Center & Practice Exams
Leverage industry resources such as the HVACR Education Resource Center or Network, which often provide free or low-cost practice exams and study guides.
Organizations like HVAC Excellence (ESCO Institute) and North American Technician Excellence (NATE) offer practice questions that, while not specific to the Tennessee contractor exam, cover many of the core HVAC topics. Practicing with these can improve your problem-solving speed and knowledge retention.
For instance, the ESCO Group’s HVACR Education Resource Network (HERN) provides online practice quizzes that can help identify areas where you need more study.
Treat practice exams like the real thing: time yourself and simulate the open-book conditions. This will help build stamina for the long exam and train you to manage your time per question.
Local Trade Schools and Community Colleges
Many aspiring licensees boost their preparation by enrolling in exam prep courses. In Tennessee, local trade schools and community colleges often offer HVAC programs or specific contractor exam prep classes.
For example, the Tennessee College of Applied Technology (TCAT) campuses and community colleges in Nashville, Chattanooga, and other areas have HVAC training programs that include coursework in load calculations, electrical controls, and refrigeration – all directly relevant to the exam.
Some schools partner with the state or approved providers to run intensive exam prep workshops. While there isn’t an “exam waiver” course for the HVAC trade exam, completing a reputable HVAC program or a dedicated prep class will greatly increase your confidence. These courses often provide guided review of the reference books, teach test-taking strategies, and sometimes include a simulated exam.
When choosing a prep course, look for ones that are recognized by the Tennessee Board for Licensing Contractors as approved prep providers. For instance, @HomePrep/Stautzenberger College (an online provider) is officially licensed by the Board as a pre-license course provider.
Experience as a Study Tool
Lastly, don’t underestimate the value of real-world experience in preparation. If you have been working in HVAC for a few years, you’ve likely encountered many of the scenarios the exam will ask about. Try to connect the questions in your practice to jobs you’ve done or seen.
For example, when studying load calculations, apply the methods to a house you worked on last summer. When reviewing electrical diagrams, think back to wiring an air handler or installing a thermostat. This practical context makes it easier to remember the right answers.
If you lack certain experiences (say, you’ve done mostly residential and little commercial), consider talking to colleagues or mentors who have that knowledge, or even take on some side tasks to get exposure. Over time, this combination of book study and hands-on practice will make you well-rounded.
From Exam to Excellence: Working with a Licensed HVAC Contractor
At Wonder Cooling, we take pride in being part of the select group of fully licensed HVAC contractors in Eastern Tennessee. Our team has gone through the rigorous testing and licensing process described above, which reflects our commitment to top-notch service and professionalism.
We stay up-to-date on Tennessee’s HVAC codes and best practices (the same knowledge that the state exams cover) so that every installation or repair we perform is done right the first time.
If you’re looking for a trusted, licensed HVAC contractor in the Eastern Tennessee region, look no further than Wonder Cooling
