This is general information, not legal advice. It summarizes Nevada statutes and NSCB guidance as of October 2026. For a specific situation, contact the NSCB or a Nevada attorney.
Most homeowners never think to check a license until something goes wrong. In Nevada, checking first matters more than in many states, because the consequences of hiring an unlicensed contractor land partly on you. This guide walks through the NSCB license search, explains which license class covers heating and cooling work, and is honest about the open question of whether pure duct cleaning needs a license at all.
A note on who we are: Reno Air Duct Cleaning is a referral service, not a contractor, and is not licensed by the Nevada State Contractors Board. We connect Reno-area homeowners with independent local duct cleaning and HVAC companies for free, no-obligation quotes, and we don't do the work ourselves. That is exactly why we encourage you to check any company you hire.
Why it matters: what NSCB says about unlicensed contractors
The NSCB's "Working With Contractors" page is blunt:
- "Contracting without a valid state contractor's license is a crime in Nevada."
- "If you hire an unlicensed contractor, your contract is null and void by law." (The statute, NRS 624.700, says such a contract "shall be deemed void ab initio.")
- "Unlicensed contractors do not carry Workman's Compensation insurance," and "you have very little recourse if something goes wrong with your project."
- "Homeowners who use unlicensed contractors are not eligible for the Residential Recovery Fund."
Step 1: Get the company's exact name and license number
Nevada makes this easy in principle. NRS 624.720(4) says: "All advertising by a licensed contractor must include the name of the contractor's company and the number of the contractor's license." The NSCB's advertising notice lists websites, vehicles, business cards, signs and online directories among the places that number must appear.
So start with the ad, the website or the truck. If the number isn't there, ask for it. A company that can't or won't give you a license number has told you something important. And note that NRS 624.720(5) makes it unlawful to advertise using a license number that doesn't belong to you, which is why you should check that the number matches the company's name.
Step 2: Search the NSCB database
Go to the NSCB website (nvcontractorsboard.com) and open the License Search, linked from the board's FAQ and resources pages. You can search by license number or business name. When you find the listing, check four things:
Status is active
An expired, suspended or revoked license doesn't count.
The name matches
NSCB says to check "that their name is the same as that on the license." A different business name can mean someone is borrowing a number.
The classification fits the job
For heating, cooling and ductwork, look for a C-21 license, typically the C-21b air-conditioning subclassification (more on this below).
The monetary limit covers your project
Nevada licenses carry a limit on job size. Make sure your quote is within it.
If anything looks off, call NSCB Licensing: (775) 688-1141 in Northern Nevada or (702) 486-1100 in Southern Nevada, Monday through Friday, 7:00 AM to 4:00 PM, per the board's website.
Step 3: Understand the C-21 classification
Nevada has no separate license class for air duct cleaning. Heating and air-conditioning work generally falls under the C-21 classification in NAC 624.380, which has seven subclassifications: C-21a Refrigeration, C-21b Air-Conditioning, C-21c Sheet Metal, C-21d Maintenance, C-21e Solar Air-Conditioning, C-21f Chilled and Hot Water Systems and C-21g Industrial Piping.
The closest fit for ductwork is C-21b, which the regulation describes as "the installation, repair, service and maintenance of equipment, devices, machinery, units and related ductwork which use evaporation, refrigeration, boilers or combustion for the control of air temperatures in structures." The word "evaporation" means evaporative (swamp) cooler service sits inside it too.
You may see "C-21d" described online as a duct cleaning license. It isn't. NAC 624.380 describes C-21d as maintenance: "the repair and replacement of any parts of existing units or systems of air-conditioning and refrigeration."
Some work is clearly HVAC contracting: duct sealing and repair, coil or blower work that involves removing parts, furnace and AC service, and swamp cooler repair. For those, a matching C-21 license is the thing to look for. See our pages on duct sealing and repair, furnace and coil cleaning and swamp cooler service.
The open question: does pure duct cleaning need a license?
Honestly, it isn't settled. Nevada's definition of a contractor (NRS 624.020) covers anyone who will "construct, alter, repair, add to, subtract from, improve" a building. "Clean" isn't on that list, which is the argument that cleaning alone isn't contracting. On the other side, C-21b expressly covers "service and maintenance of… related ductwork." We found no NSCB ruling, FAQ or advisory opinion on duct cleaning specifically, and third-party websites disagree with each other.
The practical answer for homeowners: ask the company directly whether it holds an NSCB license and in what classification, and check it on the NSCB search. If they say no license is needed for the work they're quoting, you can call NSCB and ask yourself.
The $1,000 "handyman" exemption doesn't cover HVAC work
Nevada does exempt small jobs. NRS 624.031 exempts work to repair or maintain property worth less than $1,000, including labor and materials. But the exemption doesn't apply if "the work is of a type performed by a plumbing, electrical, refrigeration, heating or air-conditioning contractor," if a building permit is required, or if the job is part of a larger project. NSCB's handyman FAQ says the same.
In other words, a low price doesn't make HVAC-type work exempt. A $300 job on your furnace or ductwork is still HVAC-type work.
Other checks worth making
- City or county business license. The City of Reno requires contractors doing business in the city to hold a Reno business license (the state license comes first). Sparks and unincorporated Washoe County issue their own.
- Proof of insurance. Ask for a certificate of insurance and read the dates.
- NADCA membership, if they claim it. NADCA says members must have at least one Air Systems Cleaning Specialist (ASCS) on staff. Confirm it in NADCA's "Find a Professional" directory rather than taking a logo on faith.
- "EPA certified" claims. Treat these as a red flag. EPA says it "neither establishes duct cleaning standards nor certifies, endorses, or approves duct cleaning companies."
- Three written estimates. EPA recommends talking to at least three providers and getting written estimates and a written agreement on cost and scope before work begins.
Red flags NSCB warns about
NSCB's advice applies to duct cleaning as much as to remodeling: "Beware of any bid, which is substantially lower than others." "Don't let a contractor or salesperson rush you into anything." "Do not engage in verbal agreements for repairs or additional work." Those line up closely with NADCA's warnings about "$99 whole house specials" and "blow-and-go" companies, covered in our post on the $99 duct cleaning scam.
Putting it together
Nevada requires contractors to show their license number in their ads; check any company on the NSCB license search before you hire. Match the name, confirm the license is active, check that the classification fits the work, and get everything in writing. It takes a few minutes and protects your contract, your recourse and your home.
When you're ready, request free quotes from independent local companies serving Reno, Sparks and the Truckee Meadows, then run each one through the steps above. You can also read more about how our referral service works.