California HVAC requirements cover five things that matter to homeowners and tenants: a minimum heating standard for every rental unit, energy-efficiency rules under Title 24 for anything newly installed, a federal refrigerant transition that reshapes equipment choices starting in 2026, mandatory air filtration in new construction, and licensing and permit rules that govern who can do the work and how it gets signed off. Cooling, notably, is not on that list at the state level.
Minimum Heating in Every Dwelling
California classifies a home without working heat as a substandard building under the Health and Safety Code, meaning it endangers the life, health, or safety of its occupants.1California Legislative Information. California Health and Safety Code 17920.3 The California Residential Code sets the technical floor: the heating system must hold every habitable room at 68°F or above, measured three feet above the floor and two feet from any exterior wall.2International Code Council. 2022 California Residential Code – R303.10 Required Heating
Portable space heaters don’t count. The code requires a permanent, fixed heating source to meet the 68°F benchmark.2International Code Council. 2022 California Residential Code – R303.10 Required Heating A landlord who leaves heat broken can face repair orders, fines, and in extreme cases condemnation of the property by local code enforcement.
No Statewide Cooling Requirement
State law does not require landlords to provide or maintain air conditioning. There is no habitability statute setting a maximum indoor temperature. In 2025 the California Department of Housing and Community Development recommended that the state adopt an 82°F maximum safe indoor air temperature for residential units, but that recommendation has not become law.3California Department of Housing and Community Development. Policy Recommendations: Recommended Maximum Safe Indoor Air Temperature
Some local jurisdictions have their own heat protections, so a city or county municipal code is worth checking in hot climate zones. If a unit came with AC and it later breaks, the landlord’s duty to repair it may fall under the general implied warranty of habitability, but the legal footing is weaker than it is for heating.
Tenant Remedies When Heat Fails
The implied warranty of habitability requires landlords to keep rental units fit for human occupation, and working heat is part of that standard.4California Department of Real Estate. Tenants Responsibility for Repairs After giving the landlord notice and a reasonable time to repair, a tenant has several options:
- Repair and deduct. Pay for the fix and subtract the cost from rent, up to one month’s rent, usable twice in any 12-month period.
- Rent withholding. Stop paying some or all of the rent until repairs are made, provided the defect threatens health or safety.
- Abandonment. Move out of a seriously defective unit; done properly, no further rent is owed after vacating.
- Lawsuit. Sue the landlord for damages. Claims under $12,500 can go through small claims court.
Each remedy requires written notice first and a reasonable period for the landlord to act. Withholding rent without documentation is a common way tenants lose eviction cases they would otherwise win.
Energy Efficiency Under Title 24
Any new HVAC installation has to meet the performance requirements in the Energy Code, Title 24, Part 6 of the California Code of Regulations.5California Energy Commission. Building Energy Efficiency Standards The 2022 cycle took effect January 1, 2023, and introduced the SEER2 and EER2 efficiency metrics. Older SEER and EER ratings no longer satisfy compliance.
For residential split-system air conditioners and heat pumps under 65,000 BTU/h, the minimums are:
- Under 45,000 BTU/h: SEER2 of 14.3 and EER2 of 11.7 (or 9.8 for systems rated SEER2 15.2 or higher).
- 45,000 BTU/h and above: SEER2 of 13.8 and EER2 of 11.2 (or 9.8 at SEER2 15.2+).
Heat Pump Baseline for New Homes
The 2022 Energy Code shifted the prescriptive baseline toward heat pumps for new single-family construction. Depending on climate zone, the baseline assumes a heat pump for either space heating or water heating. Gas equipment is still permitted, but it has to be offset elsewhere in the building’s energy budget under the performance compliance path. All-electric is now the path of least resistance for new construction across most of the state.
Thermostats, Ducts, and Filtration
Programmable setback thermostats are required so the system automatically adjusts when the home is unoccupied. Ductwork running through unconditioned spaces must be insulated to prevent thermal loss. And new residential construction must use MERV 13 (Minimum Efficiency Reporting Value) filters for both supply and return air under Energy Code Section 150.0(m)12.6California Energy Commission. 2019 Whats New for Residential MERV 13 captures fine particulate matter including pollen, mold spores, and smoke particles. When replacing a system in an existing home, confirm the equipment can handle MERV 13 filters without excessive static pressure.
Refrigerant Rules Changing in 2026
The biggest near-term shift for anyone replacing equipment is federal. Under the EPA’s Technology Transitions Program implementing the AIM Act, manufacture of new residential air conditioning products using R-410A was prohibited starting January 1, 2025. An interim rule allowed pre-2025 equipment to be installed through December 31, 2025.7U.S. Environmental Protection Agency. Frequent Questions on the Phasedown of Hydrofluorocarbons
After January 1, 2026, any new residential split system must use a refrigerant with a global warming potential below 700.8U.S. Environmental Protection Agency. Regulatory Actions for Technology Transitions The replacements are primarily R-454B (GWP 466) and R-32 (GWP 675). Both are classified A2L: low toxicity, mildly flammable. A complete system replacement in 2026, meaning both the outdoor condensing unit and the indoor coil, must use one of these lower-GWP refrigerants.7U.S. Environmental Protection Agency. Frequent Questions on the Phasedown of Hydrofluorocarbons
Existing R-410A systems are not affected. You can maintain, repair, and recharge current equipment with R-410A for the life of the system. Replacement components manufactured after January 2025 must be labeled “for servicing existing equipment only,” but they are not banned. The phase-out targets new complete systems, not repairs to equipment already in place.
Contractor Licensing
Performing contracting work totaling $500 or more without a license from the Contractors State License Board is a criminal misdemeanor in California.9Contractors State License Board. California License and Contracting Requirements for Online Home Improvement Marketplace Companies The classification for HVAC work is the C-20 license, which authorizes a contractor to fabricate, install, maintain, and repair warm-air heating, ventilation, and air conditioning systems along with their ductwork, controls, and filters.10Contractors State License Board. C-20 – Warm-Air Heating, Ventilating and Air-Conditioning Contractor
Every licensed contractor must carry a $25,000 contractor’s bond.11Contractors State License Board. Bond Requirements A contractor with even one employee must carry workers’ compensation insurance; letting that coverage lapse triggers an automatic license suspension, and any work performed while suspended counts as unlicensed work.12Contractors State License Board. Workers Compensation Requirements
Penalties for Unlicensed Work
Under Business and Professions Code Section 7028, a first conviction carries a fine up to $5,000, up to six months in county jail, or both. A second conviction raises the minimum jail time to 90 days with a fine equal to the greater of $5,000 or 20 percent of the contract price. A third conviction carries a minimum fine of $5,000 (maximum $10,000 or 20 percent of the contract price) and 90 days to one year in jail.13California Legislative Information. California Business and Professions Code 7028 The CSLB can also issue civil citations with fines ranging from $200 to $15,000 per offense.9Contractors State License Board. California License and Contracting Requirements for Online Home Improvement Marketplace Companies
Verifying a License
The CSLB issues a pocket license card when a contractor receives, renews, or reactivates a license.14Contractors State License Board. Wall Certificates and Pocket Cards A card alone isn’t proof. A suspended contractor can still show an older card from a prior renewal. Use the CSLB’s online Check a License tool before signing anything; it shows current status, bond and insurance dates, and any complaint history in real time.
Permits, Compliance Certificates, and HERS Testing
Nearly every residential HVAC installation or replacement in California needs a building permit from the local jurisdiction. The contractor (or homeowner, for owner-occupied property) submits the application along with the CF1R compliance document and pays the fee. Permit costs for a standard residential replacement typically run $200 to $500, though fees vary across California’s hundreds of permitting authorities.
Three certificates follow the project from design through verification:15California Energy Commission. 2025 Energy Code Compliance Documents – Forms for Single Family
- CF1R, the Certificate of Compliance, generated during design to prove the proposed system meets Title 24.
- CF2R, the Certificate of Installation, completed by the installing contractor to confirm the hardware matches the approved design.
- CF3R, the Certificate of Verification, completed after a third-party rater performs field verification and diagnostic testing.
Projects requiring field verification must register these forms with an Energy Code Compliance Provider before submission to the local building department. The third-party testing typically includes a duct leakage test; sealed duct systems must not leak more than 6 percent of fan flow under the California Green Building Code. Budget $150 to $500 for HERS testing separately from the installation cost. The permit cannot be finalized without the CF3R.
Once installation is complete, the inspector verifies the equipment matches the permitted plans, checks electrical and gas connections, and reviews the HERS documentation. Anything out of alignment triggers a correction notice before sign-off.
What Skipping the Permit Costs You
Unpermitted HVAC work creates problems that often surface years later. Most major equipment manufacturers condition the warranty on a permitted installation, so skipping the permit can void coverage on a system that cost thousands. Insurance carriers can deny claims tied to unpermitted mechanical work, leaving the homeowner exposed if a faulty installation causes water damage, fire, or carbon monoxide problems.
At sale, a home inspector will typically flag the system, and buyers routinely demand correction before closing or negotiate a price reduction. Retroactive permitting is possible but expensive: the permit fee often carries a penalty surcharge, and the follow-up inspection tends to be more thorough than a standard one. If the installation doesn’t meet current code, bringing it into compliance can mean opening walls or ceilings to reach ductwork and wiring that were sealed up long ago.