# How to Get an HVAC License in California: The CSLB C-20 Contractor License

California's HVAC license is the C-20 Warm-Air Heating, Ventilating and Air-Conditioning contractor license from the Contractors State License Board (CSLB). You need four years of experience in the trade, a closed-book C-20 exam plus the Law and Business exam at PSI, a $25,000 bond and workers' comp, which C-20 contractors can't opt out of.

## Key takeaways

- The C-20 is a contractor license. California doesn't run a separate state certification for HVAC technicians the way DIR certifies electricians.
- Anyone handling refrigerant still needs federal EPA Section 608 certification.
- C-20 is the only CSLB classification licensed for HVAC system heat pumps; heat pump water heaters can be C-20 or C-36.
- C-20 contractors may not file a workers' comp exemption, even with no employees.
- Costs: $450 application, $200 or $350 initial license, $25,000 bond; renewal every two years at $450 or $700.

## Who licenses HVAC work in California?

The Contractors State License Board. Its [C-20 classification](https://www.cslb.ca.gov/about_us/library/licensing_classifications/Licensing_Classifications_Detail.aspx?Class=C20) covers a contractor who "fabricates, installs, maintains, services and repairs warm-air heating systems and water heating heat pumps," plus ventilation and air-conditioning systems with their ducts, registers, flues, controls and filters. It "shall include warm-air heating, ventilating and air-conditioning systems which utilize solar energy."

For the people turning wrenches, the rule that applies statewide is federal: technicians who handle refrigerant need [EPA Section 608 certification](https://www.epa.gov/section608). We found no state-issued HVAC technician license on CSLB's site. Some cities may have their own rules for mechanical work, so ask the building department where you work.

> **Last verified**
>
> Each requirement links the CSLB page or document it came from, checked on 2026-10-24.

## Who can install heat pumps in California?

This comes up constantly as heat pumps replace gas furnaces. Per CSLB, the C-20 is the classification licensed for HVAC system heat pumps. Heat pump water heaters can be installed by a C-20 (which includes "water heating heat pumps") or a C-36 plumber (which includes "any type of equipment to heat water"). A B General Building contractor may take the prime contract but must subcontract the heat pump work to a C-20 or C-36 unless the job includes two or more unrelated trades. A C-10 electrician can do the panel upgrade but "may not contract for a heat pump water heater or HVAC system heat pump" ([CSLB fast facts](https://www2.cslb.ca.gov/Resources/GuidesAndPublications/2023/Fast_Facts_for_Heat_Pump_Water_Heaters_and_HVAC_Heat_Pumps.pdf)).

## What does a C-20 license require?

**California C-20 HVAC contractor: requirements and costs (CSLB)**

| Requirement | Detail |
| --- | --- |
| Experience | At least 4 years in the classification; up to 3 years of credit for technical training, at least 1 year practical ([CSLB](https://www.cslb.ca.gov/contractors/applicants/contractors_license/exam_application/experience_for_exam.aspx)) |
| Exams | Law and Business + C-20 trade exam, at PSI, 3½ hours each ([CSLB exam FAQ](https://www.cslb.ca.gov/About_us/Examination_FAQ.aspx)) |
| Trade exam format | Closed book, multiple choice; Planning and Estimating 22%, Fabrication/Installation/Startup 38%, Troubleshooting/Repair/Maintenance 20%, Safety 20% ([C-20 study guide](https://www2.cslb.ca.gov/Resources/StudyGuides/C20StudyGuide.pdf)) |
| Application fee | $450 ([CSLB fees](https://www.cslb.ca.gov/about_us/library/fees.aspx)) |
| Initial license fee | $200 sole owner, $350 other entities ([CSLB](https://www.cslb.ca.gov/contractors/applicants/contractors_license/exam_application/Issuing_My_License.aspx)) |
| Renewal (every 2 years) | $450 sole owner, $700 other entities ([CSLB fees](https://www.cslb.ca.gov/about_us/library/fees.aspx)) |
| Contractor bond | $25,000 ([CSLB](https://www.cslb.ca.gov/contractors/applicants/contractors_license/exam_application/Issuing_My_License.aspx)) |
| Workers' compensation | Required; C-20 contractors "may not submit an exemption" ([CSLB](https://www.cslb.ca.gov/contractors/applicants/contractors_license/exam_application/Issuing_My_License.aspx)) |

_Verified against CSLB on 2026-10-24. The C-20 study guide applies to exams scheduled on or after April 1, 2026._

## How do you get a C-20 license, step by step?

1. **Get EPA 608 certified and start working** You can't legally handle refrigerant without it. Our [EPA 608 Core practice test](https://www.brix.so/practice/epa-608/core) covers the Core section.
2. **Build four years of HVAC experience** Experience must be in the C-20 trade at journey level or higher (foreman, supervisor, contractor or owner-builder). Technical training can count for up to three years; at least one year must be hands-on ([CSLB](https://www.cslb.ca.gov/contractors/applicants/contractors_license/exam_application/experience_for_exam.aspx)). Whoever certifies your experience must have direct knowledge of it.
3. **Apply to CSLB with the $450 fee** Once CSLB accepts the application, you have 18 months to pass the exams ([CSLB exam FAQ](https://www.cslb.ca.gov/About_us/Examination_FAQ.aspx)).
4. **Pass Law and Business and the C-20 exam at PSI** Each exam allows 3½ hours. The C-20 exam is closed book and includes load and psychrometric calculations, duct design and Cal/OSHA safety ([C-20 study guide](https://www2.cslb.ca.gov/Resources/StudyGuides/C20StudyGuide.pdf)). Fail one and you can retake it after 21 calendar days ([CSLB exam FAQ](https://www.cslb.ca.gov/About_us/Examination_FAQ.aspx)).
5. **Post your bond, prove workers' comp and pay the license fee** After passing you get a bond and fee letter. Post the $25,000 contractor bond, file workers' comp (no exemption for C-20) and pay the $200 or $350 initial fee, which covers two years ([CSLB](https://www.cslb.ca.gov/contractors/applicants/contractors_license/exam_application/Issuing_My_License.aspx)).

## Do you need a license for small HVAC jobs in California?

Usually yes. Since January 1, 2025 the minor work exemption covers jobs under $1,000 in labor and materials, but only if the work needs no permit and the unlicensed person hires no workers ([CSLB bulletin](https://www.cslb.ca.gov/Resources/IndustryBulletins/2024/AB%202622%20Implementation.FINAL.pdf)). Ask the local building department whether an equipment swap needs a permit; if it does, the exemption doesn't apply, no matter how small the job.

## Does California accept HVAC licenses from other states?

Partly. CSLB's reciprocal classification list maps Arizona's C-39 and Nevada's C-21 and C-1f air conditioning licenses to the C-20. With reciprocity CSLB "may waive the trade portion of the exam," but you still take California's business law exam ([CSLB reciprocity](https://www.cslb.ca.gov/contractors/applicants/reciprocity/reciprocal_classifications_list.aspx)).

## Starting your own HVAC company in California

- **Workers' comp from day one:** C-20 is one of the classifications CSLB won't exempt, so price the policy into your startup budget ([CSLB](https://www.cslb.ca.gov/contractors/applicants/contractors_license/exam_application/Issuing_My_License.aspx)).
- **Electrical work:** panel upgrades for heat pumps belong to a C-10. See [California electrician licensing](https://www.brix.so/licensing/electrician/california).
- **Taxes:** California sales and use tax on equipment you install, and entity filing, are in [California contractor taxes and licensing](https://www.brix.so/taxes/california).
- **Business setup:** trucks, pricing, maintenance plans and first customers are in [how to start an HVAC business](https://www.brix.so/start/hvac).

BRIX tracks licenses, bonds, insurance certificates and permits and flags renewals before they lapse. It also answers calls while you're on a roof in Fresno in July, books the job and sends the quote and invoice from one customer record.

- [Compliance and permit tracking](https://www.brix.so/#use-cases): Tracks licenses, safety documents and permits and flags renewals before they lapse.
- [AI receptionist](https://www.brix.so/features/ai-receptionist): Answers every call 24/7, qualifies the caller, books the job and texts back anyone it misses.
- [Quotes and estimates](https://www.brix.so/features/quotes-estimates): Builds accurate quotes on site and follows up on every open estimate.
- [Invoicing and payments](https://www.brix.so/features/invoicing-payments): Turns finished jobs into invoices and politely chases unpaid ones until the money is in your account.

## Frequently asked questions

### Do you need a license to do HVAC in California?

To contract HVAC work you need a CSLB C-20 Warm-Air Heating, Ventilating and Air-Conditioning license, unless the job qualifies for the under-$1,000 minor work exemption with no permit and no workers. Technicians handling refrigerant also need EPA Section 608 certification.

### How long does it take to get a C-20 license?

CSLB requires at least four years of experience in the classification at journey level or above. Up to three years can be credited for technical training, but at least one year must be practical. After CSLB accepts your application you have 18 months to pass the exams.

### Is the C-20 exam open book?

No. CSLB's study guide says the C-20 exam is closed book with no reference materials. It's multiple choice, covering planning and estimating, installation and startup, troubleshooting and maintenance, and safety.

### Do C-20 contractors need workers' comp in California?

Yes. CSLB lists C-20 among the classifications that may not submit a workers' compensation exemption, so you need a policy or a certificate of self-insurance even if you have no employees.

### Who can install a heat pump in California?

CSLB says HVAC system heat pumps fall under the C-20. Heat pump water heaters can be installed by a C-20 or a C-36 plumbing contractor. A general building contractor must subcontract the work unless the job involves two or more unrelated trades.

### How much does a California HVAC license cost?

CSLB charges a $450 application fee, a $200 initial license fee for sole owners or $350 for other entities, and active renewals of $450 or $700 every two years. You also need a $25,000 contractor bond and workers' comp.

## Related

- [HVAC License Requirements by State: Technician Rules, Contractor Classes and Size Limits](https://www.brix.so/licensing/hvac)
- [How to Get a Contractor License in California: CSLB Classes, Exams, Fees and Bonds](https://www.brix.so/licensing/contractor/california)
- [How to Become a Certified Electrician in California: DIR Certification and the C-10 License](https://www.brix.so/licensing/electrician/california)
- [How to Get an HVAC License in Texas: TDLR Registration, Certification and Contractor Classes](https://www.brix.so/licensing/hvac/texas)
- [How to Get an HVAC License in Florida: Class A, Class B and Mechanical Contractors](https://www.brix.so/licensing/hvac/florida)
- [California Contractor Taxes and Licensing Guide](https://www.brix.so/taxes/california)
- [How to Start an HVAC Business in 2026 (Costs, Licenses and First Customers)](https://www.brix.so/start/hvac)
- [EPA 608 Certification: Who Needs It and How to Get It](https://www.brix.so/certifications/epa-608)
- [BTU Calculator](https://www.brix.so/tools/btu-calculator)
- [AC Tonnage Calculator](https://www.brix.so/tools/hvac-tonnage-calculator)

## Change log

- 2026-10-24: Page published. C-20 scope, heat pump rules, experience, exam, fees, bond, workers' comp, reciprocity and minor work exemption verified against CSLB.

## Sources

- [CSLB — C-20 Warm-Air Heating, Ventilating and Air-Conditioning classification](https://www.cslb.ca.gov/about_us/library/licensing_classifications/Licensing_Classifications_Detail.aspx?Class=C20) (checked 2026-10-24)
- [CSLB — Fast Facts: heat pump water heaters and HVAC heat pumps](https://www2.cslb.ca.gov/Resources/GuidesAndPublications/2023/Fast_Facts_for_Heat_Pump_Water_Heaters_and_HVAC_Heat_Pumps.pdf) (checked 2026-10-24)
- [CSLB — C-20 examination study guide (April 2026)](https://www2.cslb.ca.gov/Resources/StudyGuides/C20StudyGuide.pdf) (checked 2026-10-24)
- [CSLB — List of all fees](https://www.cslb.ca.gov/about_us/library/fees.aspx) (checked 2026-10-24)
- [CSLB — Examinations FAQ](https://www.cslb.ca.gov/About_us/Examination_FAQ.aspx) (checked 2026-10-24)
- [CSLB — Qualifying experience for the examination](https://www.cslb.ca.gov/contractors/applicants/contractors_license/exam_application/experience_for_exam.aspx) (checked 2026-10-24)
- [CSLB — Issuing my license (bonds, workers' comp)](https://www.cslb.ca.gov/contractors/applicants/contractors_license/exam_application/Issuing_My_License.aspx) (checked 2026-10-24)
- [CSLB — Reciprocal classifications list](https://www.cslb.ca.gov/contractors/applicants/reciprocity/reciprocal_classifications_list.aspx) (checked 2026-10-24)
- [CSLB — Minor work exemption rises to $1,000 (AB 2622)](https://www.cslb.ca.gov/Resources/IndustryBulletins/2024/AB%202622%20Implementation.FINAL.pdf) (checked 2026-10-24)
- [EPA — Section 608 technician certification](https://www.epa.gov/section608) (checked 2026-10-24)

Last verified against [Contractors State License Board](https://www.cslb.ca.gov/about_us/library/licensing_classifications/Licensing_Classifications_Detail.aspx?Class=C20) on 2026-10-24.

Talk to BRIX: call or text (518) 588-1122, email eeharris2004@gmail.com, or book a 15-minute call at https://cal.com/ethanharris/15min.

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Written by BRIX Editorial Team. Last updated 2026-10-24. General information, not tax, legal or financial advice.
Canonical: https://www.brix.so/licensing/hvac/california