Licensing & Your Rights
Plain-language summary of the California rules that protect you when you hire HVAC work. This is general information, not legal advice; laws change, so verify with the CSLB or an attorney.
Last updated: 2026-09-15
This page summarizes public laws for general information and is not legal advice. Laws change; always verify with the CSLB or an attorney.
When a license is required
Any HVAC project over the current CSLB threshold (labor + materials) requires a licensed contractor. Confirm the current threshold and date at cslb.ca.gov.
License classes
C-20 HVAC; C-38 Refrigeration; C-4 Boiler/Hot Water/Steam; C-2 Insulation; C-10 Electrical for related wiring; B General Building for multi-trade projects. Refrigerant handling also requires federal EPA Section 608 certification.
License number on advertising (B&P §7030.5)
The license number must appear on all advertising, including vehicles, websites, and business cards. If it is missing, that is a red flag.
Home improvement contracts (B&P §7159)
Contracts over $500 must be in writing and include required notices. Read everything before signing and keep a copy.
Down payment cap (B&P §7159.5)
The down payment cannot exceed 10% of the contract price or $1,000, whichever is less. Schedule payments to work completed.
Mechanics lien
Unpaid subcontractors or suppliers can file a lien against your home. Use a written contract and consider joint control or progress payments to protect yourself.
Permits and HERS verification
System replacements normally require a permit, and many require HERS verification by a third-party rater. Proper permits protect you and affect rebates, insurance, and resale.
Title 24 mechanical requirements
California's energy code sets duct sealing, efficiency, and ventilation rules for new and replacement systems. Compliance is documented at permit finalization.
Carbon monoxide detectors
Required outside sleeping areas and on every floor of dwellings with fuel-burning appliances or attached garages.
Workers' comp and bonds
Verify the contractor carries workers' compensation (if they have employees) and an active bond through the CSLB license check.
Warranties
Manufacturer warranties cover equipment defects; workmanship warranties cover the installer's labor. Many manufacturer warranties require registration within a set period.
Filing a complaint
You can file a complaint with the CSLB online. Keep your contract, receipts, photos, and correspondence.
CSLB – File a complaintRenters' repair rights (Civil Code §1942)
Renters have rights to habitable conditions, but the process and remedies are specific. Get legal advice before withholding rent or repairing and deducting.