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HERS testing on a Los Angeles AC replacement
When an AC or heat pump is replaced in California, the contractor tests the ducts and a third-party rater verifies the work. Since 1 January 2026 that rater works under the CEC's Energy Code Compliance (ECC) program, which replaced HERS. The checks are duct leakage, and in some climate zones refrigerant charge and airflow, recorded on 2025 CF2R and CF3R forms.
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What HERS, now ECC, actually is
The California Energy Commission says replacing or altering an HVAC unit needs a permit, the contractor seals and tests the ducts, and a third-party rater verifies the work, including duct leakage. (CEC)
From 1 January 2026 the CEC's Energy Code Compliance (ECC) program took over field verification from the HERS program, so the third-party rater on a 2026 change-out works under ECC. (CEC) Most people still say "HERS test", and contractors use both names.
The checks, form by form
| Check | 2025 form (installer / rater) | When it applies |
|---|---|---|
| Duct leakage | 2025-CF2R-MCH-20-H / 2025-CF3R-MCH-20-H | Ducted systems when heating or cooling components are replaced; whole system when more than 25 ft of new duct |
| Refrigerant charge | 2025-CF2R-MCH-25-H / 2025-CF3R-MCH-25-H | When a refrigerant component is altered; climate-zone dependent for ACs, all heat pumps |
| Airflow rate | 2025-CF2R-MCH-23-H / 2025-CF3R-MCH-23-H | Where charge verification applies |
| Design form | 2025-CF1R-ALT-02-E | Prescriptive alterations to space-conditioning systems, filed with the permit |
Form names from Energy Code Ace, 2025 residential forms (read 2026-10-20). Applicability: Energy Code Ace (CEC-supported), Single-Family Compliance Manual ch. 9, § 150.2(b)1E–F, 2022 code text; confirm against the 2025 code in force since 1 January 2026 (verify against the 2025 text).
Why the Valley and the coast differ
Los Angeles County spans building climate zones 6, 8, 9, 14 and 16. The coast (Santa Monica, Long Beach) is zone 6 and the San Fernando Valley zone 9, so the same change-out can carry different tests a few miles apart. Look up an address with the CEC climate zone tool.
Under Title 24 Part 6, replacing the condensing unit, air handler or coil is an alteration that triggers duct sealing. Adding more than 25 feet of new duct means the whole system must test at 10 percent leakage or less. Refrigerant charge checks apply to heat pumps everywhere and to ACs in zones 2 and 8–15.
In practice
A Valley AC change-out in zone 9 is more likely to carry a refrigerant charge check than the same job in coastal zone 6. Ask the contractor which checks apply to your address.
How the test day runs
- Permit issued with the CF1R design form.
- Installation, including duct sealing where required.
- Contractor tests and registers installation certificates (CF2R).
- ECC rater visits, repeats or samples the tests and registers CF3R verification.
- Final inspection by the building department, which looks for the registered forms.
If the ducts fail
Old attic and crawlspace ducts commonly leak. If they fail, the contractor seals and retests, or replaces sections. Published LA prices for that work: duct repair and sealing $800–$4,500; new ductwork $3,500–$8,000 (LA HVAC companies, 2026, see the cost guide).
Put it in the quote
Ask each bidder what they charge if the ducts fail, and who pays for a second rater visit. A quote silent on this leaves the most likely surprise unpriced.
What the quote should say
- Permit pulled by the contractor, office named.
- Title 24 duct sealing and testing included.
- ECC rater arranged and paid by the contractor (or stated otherwise).
- Price if ducts fail.
- Copies of the registered CF2R and CF3R forms at handover.
Published LA contractors price the permit and Title 24 paperwork line at $250–$800. See Title 24 compliance and what to inspect after installation.
Sources
- California Energy Commission, "Building Energy Efficiency Resources for Single Family Homes" (retrieved 2026-09-29)
- California Energy Commission, "Home Energy Rating System (HERS) Program" (retrieved 2026-09-29)
- Energy Code Ace (CEC-supported), Single-Family Compliance Manual ch. 9, § 150.2(b)1E–F, 2022 code text; confirm against the 2025 code in force since 1 January 2026 (retrieved 2026-09-29) — verify before relying on it
- California Energy Commission building climate zones (CA State Geoportal); zone assignment by address (retrieved 2026-09-29) — verify before relying on it
- Energy Code Ace (CEC-supported), 2025 Residential Energy Code Forms (retrieved 2026-10-20)
- Reliable Heating and Air (Woodland Hills), AC installation cost in LA and Ventura County (retrieved 2026-09-29)
- Cold Cloud (Glendale), central air cost in Los Angeles (retrieved 2026-09-29)
- E & A Mechanical (Tujunga), heat pump installation cost in Los Angeles (retrieved 2026-09-29)
Questions
Is HERS testing required for a like-for-like AC replacement?
Yes. Replacing the condensing unit, coil or air handler is an alteration under Title 24, which triggers duct sealing and testing and third-party verification.
What replaced HERS in 2026?
The California Energy Commission's Energy Code Compliance (ECC) program took over field verification from 1 January 2026.
Who hires the rater?
Usually the contractor. If you choose your own, agree it before work starts so the registry paperwork matches.
Does a failed test stop my rebate?
It can delay it: LADWP needs the final approved permit, and the permit is not finalled until the verification forms are registered.
Next step
Free quote request
Get a quote to check against these numbers
- Tell us about the job. Service, ZIP, property and timing. The form says right away if your ZIP is outside the area.
- We check the license first. Requests go only to contractors whose CSLB C-20 license we have matched on the state register. If none covers your ZIP yet, we email you and say so.
- Compare what comes back. Line the written quote up against the published ranges and the quote checklist.
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