Your Iowa HVAC license and contractor registration: what your business needs in the first 30 days

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

• Free. The full 30-day checklist is on this page, and the printable version (Google Docs, Word or PDF) 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, rule, board page, code or city document it comes from. Ask the Plumbing and Mechanical Systems Board or an Iowa attorney before you bet a job on my reading.

The contractor registration you got from DIAL is not an Iowa HVAC license. Every Iowa contractor who earns $2,000 a year from construction needs that registration, and on its own it doesn't let you install or repair heating, cooling or refrigeration for pay. HVAC is licensed by the Plumbing and Mechanical Systems Board, which licenses people (apprentice, journeyperson, master) and businesses (the contractor license). A contractor license needs a master in each discipline you work in, employed by the business and "actively in charge" of the work, plus $500,000 of public liability insurance, a $5,000 surety bond and a permanent place of business.^1,5,8 HVAC businesses are supposed to get the license and the registration on one joint application. If that's how your C number came, you hold both, and the rest of this page is your first 30 days. If you used DIAL's own $50 registration form, you probably don't have the license yet.⁹

The full checklist is further down. It's also a printable sheet with tick boxes and blanks for your license, bond, policy, permit and EPA 608 card numbers: make your own copy in Google Docs (lands in your Drive), download the Word version (.docx), or download the PDF. Pick a format, enter your email and I'll send the links.

In two years of Reddit's HVAC forums I found one Iowa voice on this, and he isn't an owner yet. He's a master still on someone's payroll: "I really use it as a “if i get fired ill just start my own company, so it benefits us both to not fire me”" (Reddit). The master license is the hard part. What a business needs on top of it is shorter, but it's spread over a statute, six rule chapters, a model code and four city codes. So this page is written from Iowa Code chapter 105, the board's rules (481 IAC chapters 426 to 434), the 2024 International Mechanical Code that Iowa adopted, DIAL's pages, EPA's refrigerant rules and the Des Moines, Cedar Rapids, Davenport and Iowa City rules, all read on November 3, 2026. The general side of the registration is in Iowa contractor registration, the paper you sign is in the Iowa contract template, the circuit to the condenser is in Iowa electrical license, and water heaters and gas piping beyond your equipment are in Iowa plumbing license.

Iowa contractor registration vs. HVAC contractor license: which one you have

Both come from DIAL, the Department of Inspections, Appeals, and Licensing. The registration comes from chapter 91C: a C number, an Iowa unemployment insurance account number (even with no employees), proof of workers' comp or a statement that you don't need it, and no exam. On its own it's $50 and renews every year. DIAL's registration page steers HVAC businesses away from it: "If your business provides any type of plumbing, mechanical, HVAC, refrigeration, sheet metal or hydronic systems services, you are required to obtain a license with the Plumbing & Mechanical Systems Board. Complete a joint application for a 3-year registration and contractor license."⁹ The joint application is $250 for the license and $150 for three years of registration, and renewing the license renews the registration.^4,8

If an old form, a bank or a general contractor asks for your registration "with the Labor Commissioner" or the "Division of Labor," it's the same registration. Until 2023, chapter 91C said a contractor "shall register with the labor commissioner." The 2023 state reorganization moved it to the director of DIAL, and today's text says "with the director."⁹ Even DIAL's own reciprocity instructions from 2020, which still rank on Google for "iowa hvac license," tell contractors to register with "Iowa Workforce Development – Division of Labor."⁹ Same C number either way.

The license side is chapter 105: "a person shall not operate as a contractor or install or repair plumbing, mechanical, HVAC, refrigeration, sheet metal, or hydronic systems without obtaining a license issued by the board." A contractor is anyone who provides those services "on a contractual basis and who is paid a predetermined amount under that contract."¹ A $129 tune-up you quoted counts. So does a fixed-price install you do as somebody's sub.

Which piece you might be missing depends on where you're starting:

• You're a master starting your own shop. You need the contractor license on top of your master license, in the discipline your master license covers. As a sole proprietor you have to be the master yourself, and the insurance and bond go in your own name ("Mary Smith DBA Mary Smith Plumbing" is DIAL's example). As an LLC or corporation they're in the company's name and cover all its work.^1,8 Apply on DIAL's license portal: $400 through December 31, 2026.⁸
• You're a journeyperson. You can't contract on your own: a journeyperson "will work under the supervision of a master licensed in the discipline."⁵ Your routes are the master exam (after two years as a licensed journeyperson) or a company that employs a master of record.⁴
• You're a plumber adding heating. Iowa's registration file lumps "Plumbing/Heating & A/C" into one class, so a new registration under that name could be either trade. Same board, same contractor license, but your company needs a master in each discipline: plumbing for plumbing, and mechanical, HVAC-refrigeration or hydronic for heating and cooling.⁵
• You're a service tech with NATE. The board's service technician HVAC specialty license ($50) covers appliance-side work only. It doesn't let you contract, and it doesn't cover installs.^4,5 More below.
• You're a handyman or remodeler without an HVAC license. Replacing a furnace, boiler or AC unit isn't "routine maintenance" under chapter 105, and that exemption only covers rental owners and their own staff anyway.¹ Sub the HVAC out.

Iowa mechanical license types: what HVAC-refrigeration, hydronic and mechanical cover

Iowa law calls HVAC people "mechanical professionals," and the mechanical license is the widest one the board issues. All its licenses run on one three-year term. The current one runs July 1, 2026 to June 30, 2029, and a new license is prorated by one sixth for each six months already gone.^4,8

Sources for the table: chapter 105,¹ the fee and licensure rules,⁴ the practice rules,⁵ DIAL's contractor and fee pages.⁸

Three things in the definitions matter more than the license names. First, the gas line is yours: "HVAC" includes "all natural, propane, liquid propane, or other gas lines associated with any component of an HVAC system," and hydronic says the same for boilers.¹ Second, the split between HVAC-refrigeration and hydronic is real. A boiler, a hot-water baseboard system or radiant floor heat is hydronic, so a company whose only master holds HVAC-refrigeration can't take boiler work until it adds a hydronic or mechanical master.^1,5 Third, there's no residential or commercial class and no dollar limit anywhere in chapter 105 or the board's rules: a thermostat and a 50-ton rooftop unit need the same license.¹

If you already passed both the HVAC-refrigeration and hydronic exams at the same level, you qualify for the mechanical license without taking the mechanical exam, and combining the two costs $50.^1,4 And the license works in every Iowa city. State licensing "shall supersede and preempt" local mechanical licensing, so a city can charge permit and inspection fees but can't make you sit its own HVAC exam.¹

Who must hold what: the master of record

Iowa ties the business to a person. An HVAC business needs "at all times a licensed master ... employed by the person and ... actively in charge" of its work, and a sole proprietor "shall be a licensed master in the applicable discipline."¹ The board calls that person the master of record.⁵ Five rules follow:

• No ownership share is required. The contractor can hold the master license or "employ at least one person holding a master license." An LLC owned by a journeyperson, or by someone outside the trade, can be a licensed contractor if it employs a master who's really in charge.¹
• One master per discipline. The company needs a master "for each discipline in which the contractor conducts business." A furnace-and-AC shop needs HVAC-refrigeration or mechanical; add boilers and it needs hydronic or mechanical too.⁵
• One company per discipline. "A master may only be a master of record for one contractor in any particular discipline at any one time," unless the board approves it in advance. A master who holds two discipline licenses can serve two companies, one per discipline.^5,8
• Six months if the master leaves. If your master quits, is fired or lets the license lapse, you can keep working for up to six months without a new one, but only if you tell the board within 30 days. DIAL takes the notice through its online contact form (company name, license number, date the relationship ended); a new master goes in on the Master of Record Certification Form.^5,8
• The master has duties too. A master of record who leaves has to tell the board and the company within 30 days, and no master, journeyperson or apprentice may knowingly work for an unlicensed contractor.⁵

If someone has asked you to be their master of record, read the definition before you sign anything: you're "responsible for the proper designing, installing, and repairing" of the company's systems and "actively in charge" of its work.⁵ The board can discipline you for "permitting another person to use the licensee's ... license number for any purpose" and for aiding unlicensed work, with civil penalties up to $5,000.⁷ A Florida owner described how it usually starts: "Was already doing sub work before I quit my day job “under someone else’s license”" (Reddit). In Iowa that only works as an employee. Under the statute's definition, a sub who installs for a fixed price is a contractor in his own right and needs his own license.¹ A later article covers being someone's master of record in full; the short version is to price it as a job you're running, not a signature.

Who supervises whom: apprentices, journeypersons, helpers and service techs

This changed in 2026. Senate File 2168, signed June 2, 2026 and in force since July 1, added a ratio for every chapter 105 trade: "A licensed journeyperson or master may employ or supervise licensed apprentices at a ratio not to exceed three apprentices to one licensee." Classroom training doesn't count against it.²

• Apprentices need an apprentice license ($50) and a spot in a registered apprenticeship. They work only under a master or journeyperson "who is also employed by the contractor" and licensed in the discipline they're working in.^1,5 Don't send one out alone: the rules require supervision, and the board decides afterwards what counted.
• Journeypersons work under a master licensed in that discipline, and the master has to "be available to supervise journeypersons or apprentices as needed."⁵ Nothing in the rules says the master must stand on the job site, so in my reading a journeyperson can run a service call or a change-out alone while a master is supervising and reachable.
• Service technicians with the HVAC specialty license can work on the appliance side alone. The license "does not allow a licensee to perform any other mechanical or HVAC-refrigeration work," and nobody can hold a specialty license and an apprentice license at the same time.⁵
• Helpers need no license for "general manual labor" while assisting a licensee, but their hours don't count toward a journeyperson license and the licensee answers for their work.^1,5 A helper who brazes, charges or wires is doing licensed work.
• Iowa City adds its own rule: only a master HVAC pulls permits, and a journeyman HVAC needs the state journeyman license to work in the city.¹⁹

Federal rules every HVAC business meets: EPA 608, A2L refrigerants, lead

EPA Section 608. Anyone who maintains, services, repairs or disposes of equipment "that could release refrigerants into the atmosphere must be certified." The test depends on the equipment: Type I for small appliances, Type II for high- and very high-pressure appliances, Type III for low-pressure appliances, or Universal for all of them. The cards don't expire.¹³ The same certification controls who can buy: "Any person servicing, installing or disposing of stationary appliances ... must be a section 608 certified technician," and the seller has to check that the buyer is one or employs one. An office manager can order on the company's account with a copy of a tech's card.¹³ Get a copy of every tech's card on file before the first supply house order.

A2L refrigerants (R-454B, R-32). EPA's Technology Transitions rule restricts high-GWP HFCs in new systems, and a rule published May 26, 2026 (effective July 27) "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."¹⁴ Iowa's side is simple: the state mechanical code is the 2024 IMC, and Iowa's amendments don't touch its refrigeration chapter.³ That chapter says "High-probability systems used for human comfort shall use Group A1 or A2L refrigerant," and that A2L equipment "shall comply with UL 484, UL/CSA 60335-2-40 or UL/CSA 60335-2-89."¹⁰ In practice, install A2L equipment to its listing and the maker's instructions; the code treats listed equipment installed that way as meeting its design and test requirements.¹⁰

Lead paint in pre-1978 homes. Iowa runs its own EPA-authorized program through DIAL. The small-job exemption names "minor heating, ventilation or air-conditioning work," but only while you disturb less than 6 square feet of painted drywall or plaster per room, 1 square foot of painted wood or 20 square feet outside, and work in the same room within 30 days counts as one project. A new return grille is usually under it; cutting several runs through old plaster usually isn't. Above the line you need a certified lead-safe renovator (eight-hour course, $60 a year) and a certified firm (free), with penalties up to $5,000 per offense.¹⁵

Where your Iowa HVAC license stops

• Water heaters. Plumbing, not HVAC: the plumbing definition includes "water heaters and vents."¹ An HVAC-only company subs them to a plumber or adds a plumbing master. The details are in Iowa plumbing license.
• Gas lines that don't serve HVAC. Your license covers the gas line to a furnace, unit heater or boiler. A line to a generator, range, dryer or water heater is "fuel gas piping" under plumbing.¹ People qualified under the state's LP gas rules don't need a license for propane equipment and its piping.¹
• The circuit. Wiring for someone else needs an electrical license. A mechanical or HVAC-refrigeration master or journeyperson is exempt from the special electrician license "to disconnect and reconnect existing air conditioning and refrigeration systems," and replacing a disconnect or breaker with the same size and type, with no wiring change, is routine maintenance anyone may do.^1,11 A new circuit, a bigger breaker for a heat pump, or the circuit for a mini-split goes to an electrician. Thermostat and control wiring on a Class 2 power-limited circuit is outside the electrical license law altogether.¹¹ Des Moines lets an HVAC journeyperson or master connect equipment to "an existing individual branch circuit," and limits them to electrical work on parts of the HVAC equipment itself.¹⁶ Whether the line-voltage cable between mini-split heads counts as part of the equipment isn't settled in state law, so ask the electrical inspector or let your electrician run it. More in Iowa electrical license.
• Boiler fill and humidifier water. The cold-water make-up to a boiler, with its backflow preventer, is potable water piping, which is plumbing in Iowa.¹ A furnace humidifier sits in both definitions: it's part of the HVAC system, but plumbing includes "potable water treating or using equipment." I found no board guidance. Ask the board in writing before you advertise humidifier installs, or have a plumbing master on the company.
• Condensate. The condensate line is yours: the mechanical code says condensate "shall be conveyed from the drain pan outlet to an approved place of disposal," plus an auxiliary pan, an overflow drain or a water-level detection device where an overflow would damage the building.¹⁰ A new trap, standpipe or connection into the drainage piping is plumbing.¹
• Boilers in public buildings. Iowa's boiler law skips "Heating boilers in residences" and low-pressure heating boilers outside places of public assembly. In a school, church, hospital, theater or other public assembly building, the state inspects low-pressure heating boilers every year, and the owner has to give the state ten days' written notice before covered equipment goes in.¹²
• Oil heat. I found no separate oil burner license in chapter 105 or the board's rules; an oil furnace is heating, so it's under your HVAC license. I didn't research oil tank rules, so check them before you move or replace a tank.
• Building work. Iowa has no general contractor license, only the registration you already hold (the detail is in Iowa contractor registration), so framing a chase or flashing a curb needs nothing more from the state. Some cities license building contractors anyway: Davenport does.¹⁸

Iowa mechanical permits and inspections

The state of Iowa doesn't issue mechanical permits. Iowa's mechanical code rule says permit, inspection and enforcement provisions "are not administered by the Plumbing and Mechanical Systems Board or the state unless otherwise provided by law," and chapter 105 says cities don't have to inspect.^1,3 Cities that want a permit program run their own. The code still applies "in each local jurisdiction," and the board's rules make every licensee "apply for and obtain all applicable permits prior to performing any work."^1,5 Skipping a required permit is a ground for discipline.⁷ Where a city issues permits, pull one first. Where nobody does, there's no permit, the job still has to meet the code, and your photos and invoice are the only record.

The Iowa mechanical code: the 2024 IMC with Iowa amendments

Iowa adopted chapters 2 to 15 of the 2024 International Mechanical Code, effective March 26, 2025. Cities "may not adopt mechanical codes other than the state mechanical code," but they can adopt stricter amendments. For fuel gas, Iowa swaps the International Fuel Gas Code for NFPA 54, NFPA 58, the state LP gas rules and the state plumbing code.³ (Des Moines's city code still cites the 2021 IMC; the state code is what applies.^3,16) The Iowa amendments you'll meet on house jobs:³

• A level working space at least 30 by 30 inches on every side of equipment that needs service.
• Appliances in rooms and closets need a door, an unobstructed passage at least 36 inches wide and 80 inches high, and a level 30 by 30 inch service space at the front with the door open. Measure the closet before you quote a bigger furnace.
• Return air openings at least 18 inches from supply openings; one return per floor on a central duct return, per ACCA Manual D; transfer openings on bedrooms without their own return.
• Ducts in exterior walls, cantilevered floors and floors over garages separated from unconditioned space and insulated to the energy code. An air gap doesn't count toward duct R-value.

For the close-out itself (charge, airflow, combustion, the papers you leave behind), use the HVAC installation checklist.

The big four: Des Moines, Cedar Rapids, Davenport, Iowa City

• Des Moines. A mechanical permit "for any installation, alteration, repair, replacement, or remodel." The only exemption is minor repair, cleaning, adjustment or minor parts where the whole job costs $100 or less, and walk-in coolers always need a permit. Only holders of a board mechanical or plumbing contractor license get permits.¹⁶ A mechanical permit for work on an existing house is $77.25; a new house is $128.75 (2026 fees). Commercial permits are $77.25 plus unit fees, such as $15.50 for each furnace or comfort cooling unit.¹⁶
• Cedar Rapids. "In order for contractors to perform work and be issued a permit in the City of Cedar Rapids, licensing with the State of Iowa is required." The permit holder books its own inspections by email or online, by 4:00 PM the business day before, and the mechanical rough-in (heating plant, vent and ductwork) comes before the framing inspection. Mechanical inspectors: 319-286-5833.¹⁷
• Davenport. A city "Electrical, HVAC and Plumbing License" on top of the state one: "Licensing and testing by the State of Iowa," no fee, a copy of your state license and a $5,000 surety bond on the city's form, with the original mailed to 1200 E 46th Street.¹⁸ State law preempts local licensing, so I'd treat it as a registration, but the city expects it before you work there.¹
• Iowa City. "Only Master electricians, Master plumbers, and Master HVAC contractors may pull permits," and nobody may "plan for, layout, supervise or perform work as a Master HVAC" there without a state master license.¹⁹

I didn't check every town. Before the first job in a new city, call the building department and ask: do you issue mechanical permits, and what does a furnace or AC change-out need?

The gas utility

Your work starts at the meter. MidAmerican Energy's gas manual puts "all piping and equipment beyond the delivery point" (the outlet of the meter set) on the customer, and asks for advance notice of "substantial changes to load," naming a natural gas generator and a tankless water heater as examples. For new service, "The plumber, builder or owner is responsible to ensure all requirements have been met to have gas service turned on." The number it gives for turn-ons and service questions is 1-888-427-5632.²⁰ If you're adding a lot of input (a bigger furnace plus a generator, say), call before the job, not after the meter can't keep up. Other gas utilities have their own manuals; I read only MidAmerican's.

The homeowner exemption

An owner can do HVAC work on their own principal residence if it's an existing single-family home (not new construction) that qualifies for the homestead tax credit, or on their farm property, and unpaid volunteers helping them need no license either.¹ DIAL reminds owners that "local jurisdictions may still have permit or inspection requirements."⁸ Rentals, new houses and anything done for pay are outside it.

Can I take this job? An Iowa HVAC table

The verdicts assume your company holds the contractor license with an HVAC-refrigeration or mechanical master of record, the house is an existing single-family home, and it was built after 1978 unless the row says otherwise. "With a permit" means where the city issues one, because the state doesn't. If you hold only the registration, every row is "sub it out."

Sources for the table: chapter 105,¹ the mechanical code rule,³ the practice rules,⁵ the 2024 IMC,¹⁰ chapter 103,¹¹ chapter 89,¹² EPA,¹³ lead,¹⁵ the city codes and pages,^16,18,19 MidAmerican.²⁰

Your first 30 days: the Iowa HVAC contractor checklist

This is the whole list. The printable version has the same items with tick boxes and blanks for the numbers permit counters, supply houses, inspectors and general contractors ask for.

Week 1: the credentials

1. Pick the business entity. Sole proprietor, or an LLC formed by filing a certificate of organization with the Iowa Secretary of State through Fast Track Filing.²¹ A sole proprietor has to be the master and carries the insurance and bond personally; an LLC carries them in its own name.¹
2. Find out which registration you have. Note your C number. If it came from the joint application, it renews with the contractor license. If it came from DIAL's stand-alone $50 form, it renews every year and you still need the license.⁹ Look your company up on the board's public license search.⁸
3. Get the unemployment insurance number from Iowa Workforce Development, even with no employees. The application asks for it.⁸
4. Buy the $5,000 surety bond. It's a performance bond: the obligee is your customers ("licensee's Iowa customers" is wording DIAL has accepted), never the state or the board, and the surety has to give the board 10 days' notice before cancelling it.^5,8 Out-of-state contractors also file a $25,000 bond with the registration.⁸
5. Put $500,000 of public liability insurance in force. The certificate goes to the board with the certificate holder listed as "Bureau of Environmental Health & Contractor, Iowa Dept of Inspections, Appeals & Licensing, 6200 Park Ave Ste 100, Des Moines, IA 50321," and 10 days' cancellation notice to the board.⁸
6. Workers' comp before your first employee starts. The application needs a certificate listing DIAL as certificate holder once you have one or more employees.⁸
7. Apply for the contractor license on DIAL's license portal (the joint application), naming a master of record for each discipline: HVAC-refrigeration or mechanical, plus hydronic if you'll touch boilers. $400 through December 31, 2026, $333.50 from January 1, 2027, plus $25 on paper.⁸ Don't book HVAC jobs until it's issued.
8. License your crew. Apprentice licenses ($50) for anyone in a registered apprenticeship, no more than three per journeyperson or master; journeyperson licenses ($180); the service technician specialty ($50) for NATE techs doing appliance-side work. Helpers stick to manual labor.^1,2,4
9. EPA 608 cards for everyone who touches refrigerant. Note each card's type and number, and give the supply house copies so the office can order on the account.¹³

Week 2: cities, subs and the utility

10. List the towns you'll work in and call each building department: do they issue mechanical permits, how do you book inspections, and what does a furnace or AC change-out need?
11. Des Moines: set up permits with the Permit and Development Center, and budget $77.25 for a mechanical permit on an existing house.¹⁶
12. Cedar Rapids: save the inspection request address (InspectionRequests@cedar-rapids.org), the 4:00 PM cutoff the business day before, and the mechanical inspectors' line, 319-286-5833.¹⁷
13. Davenport: send the city license application, a copy of your state license and the original $5,000 bond on the city's form.¹⁸
14. Iowa City: make sure a master HVAC pulls the permits.¹⁹
15. Line up subs for what your license doesn't cover: an electrician for new circuits and mini-split power, a plumber for water heaters, generator gas lines and boiler make-up water (unless you hold those licenses), and a hydronic contractor for boilers if you have no hydronic master.
16. Gas utility: save MidAmerican's service number (1-888-427-5632), or your local utility's, for load changes and turn-ons.²⁰

Weeks 3 and 4: paperwork and habits

17. Put your contractor license number on every written ad. That's the law: "All written advertisements distributed in this state" by an HVAC business "shall include the listing of the contractor license number."¹ Iowa has no vehicle lettering rule, but the statute treats using a vehicle or an ad as a provider of HVAC services as evidence you're in the business.¹ So put the number on the truck, the website, flyers and door hangers, and the license number, master's name and C number on every quote, invoice and contract.
18. Hang the contractor license certificate where you do business, and make sure every tech carries a copy of their license or has it handy at the job site.^1,5
19. Make permits a habit. A permit line on every quote that needs one, the permit pulled before you start, and inspections booked by whoever pulled the permit.^5,17
20. Lead-safe certification if you'll open walls or ceilings in pre-1978 homes: an Iowa lead-safe renovator ($60 a year) and a certified firm (free).¹⁵
21. Ask about sales tax. DIAL's registration page points contractors to the Iowa Department of Revenue for sales and use tax; ask it how your installs and repairs are taxed before you send the first invoice.⁹
22. Put the dates on the calendar. Licenses expire June 30, 2029; renewal opens May 1, 2029. Continuing education by then: 8 hours for one mechanical-discipline license (2 safety, 2 Iowa mechanical code, 4 in the discipline), more if you hold several, up to half online. Late fees: $60 from August 1, $100 from September 1, when you also have to stop working.^4,6,8 Insurance, bond and workers' comp renewals.
23. Know what to report within 30 days: a new business address, losing your master of record (that starts the six-month clock), a criminal conviction, and any judgment or settlement of a claim related to your work.^5,7

What happens if you cross the line

HVAC work without the license

• A civil penalty of up to $5,000 per offense, and "each day of a continued violation constitutes a separate offense," though offenses from "the same or common facts or circumstances" count as one.¹ The board's list of unlicensed practices includes providing HVAC services "on a contractual basis" and running an HVAC business "without employing a licensed master."⁷
• An injunction, and the board can refer the case for criminal prosecution.^1,7
• Claiming to be licensed when you aren't, or listing someone else's license number in an ad, is a simple misdemeanor: a fine of $105 to $855 and up to 30 days in jail.^1,22
• Without the registration: DIAL citations of up to $500 for a first violation and up to $5,000 after that.⁹

If you hold a license

• The board can revoke, suspend, put you on probation or fine you up to $5,000. Grounds include contracting "without a board-issued contractor license," working as a contractor "without valid bonding or insurance," practicing in a trade you aren't licensed for (boiler work on an HVAC-refrigeration license, say), skipping a required permit, letting someone use your license, and letting an unlicensed employee do licensed work.⁷
• Your master and journeypersons are exposed too: none of them may knowingly work for an unlicensed contractor.⁵

Getting paid and insurance

Chapter 105 doesn't say a contract for unlicensed HVAC work is void, and I didn't research Iowa case law on whether a court would enforce one. Iowa's lien law says a 91C registration "shall not be required in order to post a notice or a lien," but it says nothing about the board license.²² Don't be the test case. On insurance, the $500,000 policy and the bond have to stay in force for the whole license period, and the insurer has to warn the board before cancelling.⁵ I found no Iowa rule on what unlicensed or out-of-scope work does to a claim. That's in your policy, so ask your agent in writing: "Does my policy cover work outside the license I hold?" Keep the reply.

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 it doesn't know Iowa law. It won't pull a permit, book an inspection, track continuing education or EPA 608 cards, or warn you before the bond or the insurance lapses. What it does help with: the shop-wide terms text you set once is copied onto every quote and shows on the customer's quote page, and the invoice footer is copied onto every invoice, so your contractor license number, master's name and C number go on every document without retyping. You can attach a checklist to a quote (a change-out list with the permit number, the inspection date and the tech's 608 card, say); it stays internal and editable after the customer approves. Files attached to a quote, like the permit, carry over to the job, and techs add photos to each visit. Each customer's equipment records hold the type, brand, model, serial number, year, filter size, location, fuel, AFUE and a nameplate photo, so the furnace you installed is on file when the customer calls next winter. Quotes can carry options (good, better, best), the customer approves and signs on screen, and an optional card deposit is credited on the final invoice. Free covers 30 estimates and 30 invoices a month for your whole team, with scheduling and dispatch, quotes, invoicing, card payments, and customer and equipment records; Pro is $29 a month with unlimited estimates and invoices (pricing).

Frequently asked questions

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

You can own it, but it can't operate without licenses. The business needs a contractor license from the Plumbing and Mechanical Systems Board, and it needs a licensed master who is employed by it and 'actively in charge' of the HVAC work, in each discipline it works in. No ownership share is required, so an owner without a license can hire a master. A sole proprietor has to be the master. The DIAL contractor registration (the C number) doesn't license any HVAC work on its own.

Do you need a contractor's license in Iowa for HVAC work?

Yes. Iowa has no general contractor license, only a registration, but heating, air conditioning, refrigeration, ductwork and hydronic work need a board contractor license under Iowa Code chapter 105. HVAC businesses get the license and the registration on one joint application: $400 if you apply between July 1 and December 31, 2026 ($250 for the license, $150 for three years of registration), $333.50 from January 1, 2027. You also need $500,000 of public liability insurance, a $5,000 surety bond, a permanent place of business and a master of record.

What are the requirements to get an HVAC license in Iowa?

For a person: an apprentice license while you're in a U.S. Department of Labor registered apprenticeship (18 or older, high school diploma or GED), then four years of apprenticeship and the journeyperson exam, then two years as a licensed journeyperson and the master exam. 75% passes. For the business: a master in each discipline, $500,000 public liability insurance, a $5,000 surety bond, a permanent place of business, an Iowa unemployment insurance number and, with employees, workers' comp.

What is an Iowa mechanical license?

The widest of the board's HVAC licenses. A mechanical license covers HVAC, refrigeration, sheet metal and hydronic work. The HVAC-refrigeration license covers heating, ventilation, air conditioning, ductwork and refrigeration; the hydronic license covers boilers, steam and hot or chilled water piping; sheet metal is a journeyperson license only. If you've passed both the HVAC-refrigeration and hydronic exams at the same level, you qualify for the mechanical license without the mechanical exam, and combining them costs $50.

How do I look up an Iowa HVAC or mechanical license?

DIAL's contractor license page links to a public portal where you can search or verify plumbing and mechanical licenses. Check anyone you hire, and any company before you agree to be its master of record. The contractor registration (the C number) is a separate search, and a C number without a board contractor license doesn't make a business a licensed HVAC contractor.

When does an Iowa mechanical license expire, and how do I renew it?

Every board license expires June 30 every three years. The current period runs July 1, 2026 to June 30, 2029, so a license issued now expires June 30, 2029. Renewal opens May 1, 2029. Masters and journeypersons need 8 hours of board-approved continuing education per term for one mechanical license: 2 hours of Iowa OSHA safety, 2 hours of the Iowa mechanical code and 4 hours in the discipline, up to half online. No late fee through July 31; $60 in August and you can still work; $100 from September 1, and you can't work until you renew.

What is the Iowa mechanical code?

The 2024 International Mechanical Code, chapters 2 to 15, with Iowa's amendments, in effect since March 26, 2025 (481 IAC chapter 426). It applies in every city. A city can't adopt a different mechanical code but can adopt stricter amendments. Fuel gas follows NFPA 54, NFPA 58, the state's LP gas rules and the state plumbing code instead of the International Fuel Gas Code. The state doesn't issue mechanical permits: cities with a program do.

What does the Iowa Plumbing and Mechanical Systems Board do?

It licenses plumbers, mechanical professionals and plumbing and mechanical contractors, adopts the state plumbing and mechanical codes, approves continuing education and disciplines licensees. It can fine an unlicensed person up to $5,000 per offense, with each day a separate offense, and suspend or revoke a license. It sits within DIAL at 6200 Park Avenue, Suite 100, Des Moines; the board office line is 866-280-1521 and contractor licensing is 515-281-6071.

Can a homeowner do their own HVAC work in Iowa?

Yes, on their own principal residence if it's an existing single-family home (not new construction) that qualifies for the homestead tax credit, or on their farm property, and unpaid volunteers helping them need no license either. City permits still apply where the city has a program. Rentals, new houses and anything done for pay are outside the exemption.

Sources

1. Iowa Code chapter 105, Plumbers, Mechanical Professionals, and Contractors: 105.2 (definitions: "contractor"; "HVAC" includes "ducted systems" and "all natural, propane, liquid propane, or other gas lines associated with any component of an HVAC system"; hydronic includes boilers and their gas lines; "plumbing" includes "potable water treating or using equipment ... fuel gas piping, water heaters and vents"; routine maintenance excludes "the replacement of furnaces, boilers, cooling appliances"; sheet metal), 105.4 (state mechanical code applies "in each local jurisdiction"; local jurisdictions not required to inspect), 105.10 (license required; a master "employed by the person and ... actively in charge"; sole proprietor must be a master; master mechanical covers the other mechanical licenses), 105.11 (exemptions: homeowner, LP gas, helpers, rental owners' routine maintenance, volunteers), 105.14 (display), 105.17 (preemption of local licensing; permit and inspection fees allowed), 105.18 (license types and scope; four-year apprenticeship; master after journeyperson; HVAC-refrigeration plus hydronic exams qualify for mechanical; contractor license conditions; disconnect and reconnect of existing air conditioning without a special electrician license), 105.19 (insurance and bond; 10 days' notice), 105.20 (three-year terms; at least 8 hours of continuing education), 105.22 (discipline), 105.25 (written ads must list the contractor license number; false claims a simple misdemeanor), 105.26 (injunction), 105.27 (civil penalty up to $5,000 per offense, each day separate), 105.29 (use of a "vehicle, or advertisement" as a provider is prima facie evidence of practice). legis.iowa.gov, Iowa Code 2026, read November 3, 2026.
2. Senate File 2168 (2026), Division II, new Iowa Code 105.18(5): "A licensed journeyperson or master may employ or supervise licensed apprentices at a ratio not to exceed three apprentices to one licensee"; signed June 2, 2026 (Acts chapter 1155), effective July 1, 2026. enrolled bill, bill history, read November 3, 2026.
3. Iowa Administrative Code 481, chapter 426, State Mechanical Code (IAC 9/30/26): 426.2 (2024 International Mechanical Code, sections 101 and 102 and chapters 2 to 15, adopted; ARC 8914C, effective March 26, 2025), 426.3 (amendments: fuel gas by NFPA 54, NFPA 58, 661 chapter 226 and the state plumbing code; new 102.12, permits and inspection "not administered by the Plumbing and Mechanical Systems Board or the state," local jurisdictions "may not adopt mechanical codes other than the state mechanical code"; 306.1 and 306.2 service space and closet access; 306.5 roof access; 601.5 return air; 603.1.1 duct location; 604.3 duct insulation; no amendment to chapter 11). legis.iowa.gov, read November 3, 2026.
4. Iowa Administrative Code 481, chapter 428, Licensure Fees (apprentice $50, journeyperson $180, master $240, contractor $250, specialty $50, exam application $35, paper application $25, late fees $60 and $100, combined-license 30% reduction, $50 to combine HVAC-refrigeration or hydronic into mechanical), and chapter 429, Application, Licensure, and Examination (service technician HVAC and hearth systems specialty licenses; masters need two years as a journeyperson; 75% passes; licenses "expire on June 30 every three years, beginning with June 30, 2026"; contractor renewal "constitutes registration as a contractor"). 428, 429, read November 3, 2026.
5. Iowa Administrative Code 481, chapter 431, Licensee Practice: 431.1 ("master of record"), 431.2 (license copy at the work site; "apply for and obtain all applicable permits prior to performing any work"; responsibility for helpers), 431.3 (contractor: a master "for each discipline in which the contractor conducts business," not one "simultaneously associated with another contractor in that discipline"; six-month grace period with notice within 30 days; surety bond "in a minimum amount of $5,000"; public liability insurance "in a minimum amount of $500,000"; permanent place of business; apprentices supervised by a master or journeyperson "also employed by the contractor"), 431.4 (one contractor per discipline per master; master "available to supervise"; 30-day notice on leaving), 431.5 (journeyperson works "under the supervision of a master licensed in the discipline"), 431.6 (apprentices), 431.7 (hearth systems and service technician HVAC specialty licenses; no apprentice and specialty license together); and 481-427.4(2) (change of address within 30 days). 431, 427, read November 3, 2026.
6. Iowa Administrative Code 481, chapter 432, Continuing Education (the "Iowa mechanical code" is the IMC as adopted by the board; 2 hours safety, 2 hours Iowa mechanical code and 4 hours discipline per term for a single license; up to half online). legis.iowa.gov, read November 3, 2026.
7. Iowa Administrative Code 481, chapter 434, Licensee Discipline: 434.2 (grounds, including letting another use your license number, failing to report a criminal conviction or a judgment or settlement within 30 days, aiding unlicensed practice, permitting unlicensed employees, failing to obtain a required permit, practicing outside the scope of the license, "contracting for plumbing or mechanical work in the state of Iowa without a board-issued contractor license," "practicing as a contractor without valid bonding or insurance"), 434.3 (sanctions, civil penalties up to $5,000), 434.5 (civil penalties against unlicensed persons; referral for criminal prosecution). legis.iowa.gov, read November 3, 2026.
8. DIAL, Plumbing and Mechanical Systems Board pages: "Contractor License" (definition of contractor; $500,000 public liability insurance; certificate holder address; $5,000 surety bond, obligee not the state or the board; master of record rules and certification form; joint application with registration; unemployment insurance number "even if you have no employees"; workers' comp with one or more employees; out-of-state $25,000 bond; public license search), "Licensing Period & Fees" (period July 1, 2026 to June 30, 2029; "$400.00 ($250 + $150)" and "$333.50 ($208.50 + $125)"; renewal opens May 1 of year three; late fees and eligibility to work), and "Plumbing & Mechanical Systems Licensure" (8 hours of continuing education; HVAC/R journeypersons and masters need no special electrician license; volunteer work; 866-280-1521). contractor license, fees, licensure, license portal, public license search, read November 3, 2026.
9. Iowa Code chapter 91C, Construction Contractors, 2026 (91C.1 $2,000 threshold, "director" of DIAL, chapter 105 contractors register through the combined application; 91C.2 "shall register with the director," workers' comp evidence, employer account number; 91C.8 penalties up to $500, then up to $5,000), legis.iowa.gov; Iowa Code 2023 edition, 91C.2 ("shall register with the labor commissioner"), legis.iowa.gov; DIAL, "Contractor Registration" ($50; renewed every year; plumbing and mechanical businesses use the joint application "for a 3-year registration and contractor license"; Department of Revenue for sales and use tax; penalties; 515-242-5871), dial.iowa.gov; DIAL, "Application Instructions for License by Reciprocity" (03/2020: contractors "registered with Iowa Workforce Development – Division of Labor"), dial.iowa.gov. Read November 3, 2026.
10. International Code Council, 2024 International Mechanical Code: chapter 11, Refrigeration (1101.2 and Table 1101.2, split systems "UL 1995 or UL/CSA 60335-2-40"; 1101.2.1, A2L high-probability equipment "shall comply with UL 484, UL/CSA 60335-2-40 or UL/CSA 60335-2-89"; 1104.3.1, comfort systems "shall use Group A1 or A2L refrigerant"; Table 1103.1, R-32 classed A2L), codes.iccsafe.org; chapter 3 (307.2.1 condensate "conveyed from the drain pan outlet to an approved place of disposal"; 307.2.3 auxiliary and secondary drain systems), codes.iccsafe.org. Read November 3, 2026.
11. Iowa Code chapter 103, Electricians and Electrical Contractors: 103.1(18) ("routine maintenance": same size and type, "no changes in wiring"), 103.1(19) (special electrician class for "disconnecting and reconnecting of existing air conditioning and refrigeration"), 103.11 (license to wire for another), 103.22(6), (11) and (12) (appliances on an existing supply; Class 2 and Class 3 power-limited circuits; routine maintenance). legis.iowa.gov, read November 3, 2026.
12. Iowa Code chapter 89, Boilers and Pressure Vessels: 89.3(1) (annual inspection, including low-pressure heating boilers in places of public assembly), 89.4(1)(e) and (g) (not applicable to "Heating boilers in residences" or "Low pressure heating boilers used in buildings other than those for public assembly"), 89.6(1) (ten days' written notice before installing). legis.iowa.gov, read November 3, 2026.
13. U.S. EPA, "Section 608 Technician Certification Requirements" (certification types; credentials do not expire) and "Questions and Answers about the Refrigerant Sales Restriction" (buyers must be or employ a certified technician; copies of certification cards). epa.gov, epa.gov, read November 3, 2026.
14. U.S. EPA, "Phasedown of Hydrofluorocarbons: Reconsideration of Certain Regulatory Requirements Promulgated Under the Technology Transitions Provisions of the American Innovation and Manufacturing Act of 2020," 91 FR 31284, published May 26, 2026, effective July 27, 2026, federalregister.gov; EPA, "Technology Transitions HFC Restrictions by Sector," epa.gov. Read November 3, 2026.
15. U.S. EPA, "Lead Renovation, Repair and Painting Program" (Iowa runs its own authorized program), epa.gov; Iowa Code 10A.902 (civil penalty "not to exceed five thousand dollars for each offense"), legis.iowa.gov; Iowa Administrative Code 481-470 ("minor repair and maintenance activities," "including minor heating, ventilation or air-conditioning work"; under 1 sq ft of painted wood, 6 sq ft of drywall or plaster per room, 20 sq ft outside; same room within 30 days is one project), legis.iowa.gov; DIAL, "Lead Safe Renovation and Prerenovation Notification" (eight-hour course; $60 a year per individual; firm certification free), dial.iowa.gov. Read November 3, 2026.
16. City of Des Moines: Municipal Code chapter 26 (2023 updates, markup version), 26-452(3) (HVAC journeyperson or master may connect or disconnect HVAC equipment "to an existing individual branch circuit"), 26-500 (adoption of the state mechanical code), 26-501 (mechanical permit "for any installation, alteration, repair, replacement, or remodel"), 26-502 (exemptions: walk-in refrigerating systems never exempt; minor repair, cleaning, adjustment or minor parts where the total cost does not exceed $100), 26-550 (permits only to board-licensed mechanical or plumbing contractors), 26-551 (state licensees recognized), cms2.revize.com; Permit and Development Center Permit Fees, new fees 1-1-26 (mechanical permit, existing dwelling $77.25, new dwelling $128.75; commercial base $77.25 plus unit fees), fee schedule. Read November 3, 2026.
17. City of Cedar Rapids, "Licensing for Contractors" and "Inspection Requests" (state licensing required for a permit; permit holder schedules inspections by 4:00 PM the business day before; mechanical rough-in before framing; Mechanical Code 319-286-5833). cedar-rapids.org, cedar-rapids.org, read November 3, 2026.
18. City of Davenport, "Contractor Licenses" (construction contracting license under City Code 15.30; "City of Davenport Electrical, HVAC and Plumbing License": "Licensing and testing by the State of Iowa," "No Fees Apply," copy of state license, $5,000 bond) and "Contractor Bond and Bond Instructions" ("Electrical, Mechanical, Plumbing and Sign Contractors shall furnish a bond in the sum of $5,000"; city bond form; original mailed to 1200 E 46th St). davenportiowa.com, davenportiowa.com, read November 3, 2026.
19. City of Iowa City, "Licensing Requirements" (only master electricians, master plumbers and master HVAC contractors pull permits; state master license to plan, lay out, supervise or perform master HVAC work; state journeyman license to work as a journeyman HVAC; hearth systems specialty). icgov.org, read November 3, 2026.
20. MidAmerican Energy, Gas Service Manual (effective July 9, 2018): customer responsible for "all piping and equipment beyond the delivery point"; advance notice of "substantial changes to load," such as a natural gas generator or a tankless water heater; "The plumber, builder or owner is responsible to ensure all requirements have been met to have gas service turned on"; 1-888-427-5632. midamericanenergy.com, read November 3, 2026.
21. Iowa Secretary of State, Fast Track Filing Resource Center, "How do I form an Iowa Limited Liability Company (LLC)?" help.sos.iowa.gov, read November 3, 2026.
22. Iowa Code 572.34(11) ("Registration under chapter 91C shall not be required in order to post a notice or a lien under this chapter"), legis.iowa.gov; Iowa Code 903.1(1)(a) (simple misdemeanor: fine of $105 to $855, up to 30 days), legis.iowa.gov. Read November 3, 2026.