Refrigerant Charge Verification (RCV) in California: When It's Required and How It Works

Refrigerant charge verification (RCV) is a Title 24 field test that confirms an air conditioner or heat pump holds the amount of refrigerant the manufacturer specifies and that its metering device is working. The HVAC installer charges and tests the system, and then an independent ECC-Rater (formerly HERS rater) verifies it. For permits applied for on or after January 1, 2026, the 2025 California Energy Code's prescriptive rules call for RCV on air-source heat pumps in all climate zones and on air-cooled air conditioners in Climate Zones 2 and 8 through 15, with a few equipment exceptions covered below. It applies to new homes and to alterations that replace refrigerant-containing parts. On a performance-path project, follow the verification list on your approved CF1R.

Incorrect charge, whether too much or too little, reduces capacity and efficiency and can shorten compressor life. The test exists because charge problems are common and hard for owners to spot.

In new construction, the prescriptive package in Table 150.1-A of the 2025 Standards marks refrigerant charge verification as required for heat pumps in every climate zone. For air conditioners it is required in Climate Zones 2, 8, 9, 10, 11, 12, 13, 14 and 15. The requirement for heat pumps in every climate zone is new in 2025.

In existing homes, Section 150.2(b)1F applies when an air conditioner or heat pump is altered by installing or replacing refrigerant-containing components. These are the compressor, condensing coil, evaporator coil, refrigerant metering device or refrigerant piping.

Swapping a condenser and coil during a change-out therefore triggers RCV in the climate zones above. The same alteration also requires all thermostats on the system to be replaced with setback thermostats. The rule covers ducted split systems, ducted packaged systems, small duct high velocity systems and mini-splits.

You can look up your climate zone and local raters through our climate zone directory pages. Zone 9 covers much of inland Los Angeles. Duct leakage testing is a separate requirement, explained in our duct leakage testing guide.

The Reference Residential Appendix RA3.2 defines two procedures.

The standard charge verification procedure is used when it is 55°F or warmer outside and the system is within the other operating limits in Table RA3.2-1, which include upper outdoor temperature limits and return-air conditions. For systems with a fixed metering device (a piston or capillary tube), the tester measures superheat and compares it to a target from the appendix table or the manufacturer's chart. For systems with a thermostatic expansion valve (TXV) or electronic expansion valve, the tester measures subcooling against the manufacturer's target and checks superheat to confirm the valve works. Installers must hit tighter tolerances than raters to allow for measurement differences. For subcooling, the installer must be within 3°F of target and the rater within 6°F.

The weigh-in procedure is used when it is below 55°F or when the standard procedure doesn't fit the system. The installer weighs in the charge based on the manufacturer's specification, line set length and indoor coil (RA3.2.3.1). If the system can be tested with the standard procedure, the rater still verifies it that way once conditions allow. When it is below 55°F, the installer can instead elect to have the rater observe the weigh-in (RA3.2.3.2), and the thermostat must then meet Section 110.12. Systems that can't use the standard procedure at all are verified by rater observation of the weigh-in. Observation means the rater has to be on site while the charge goes in, so schedule it before the installation, not after. Weigh-in verification can't use group sampling.

Heat pumps can only be charge-tested in cooling mode. Because charge is read across the coil, minimum airflow is verified at the same time. For alterations the minimum is 300 cubic feet per minute (cfm) per ton, or 250 cfm per ton for small duct high velocity systems. Ducted central systems in new construction generally must meet 350 cfm per ton (250 cfm per ton for small duct high velocity systems) plus a mandatory fan efficacy limit in watts per cfm (0.45 for gas furnaces, 0.58 for other air handlers, 0.62 for small duct high velocity). Our CF2R vs CF3R guide explains the installer and rater paperwork that records these results.

• Factory-charged packaged units. An entirely new or complete replacement packaged system charged and verified by the manufacturer does not need field charge verification. The installer must certify on the CF2R that it was factory charged and not altered. Ducted packaged units still need the airflow check.
• Mini-splits and systems that can't use the standard test. These follow the weigh-in route with rater verification. The 2025 manual notes that even DIY pre-charged mini-splits need RCV, because connecting the line set at the home alters the system, and that weigh-in is the right method.
• Low airflow (alterations only). Altered systems that can't meet minimum airflow have an alternative path (RA3.3.3.1.5), but it comes with thermostat requirements and no group sampling. New construction has no such exception.

Older code cycles let some systems use a fault indicator display (FID) in place of charge verification. The 2025 Single-Family Compliance Manual states that fault indicator displays "have been removed as an available method for refrigerant charge verification." If your contractor is quoting an FID approach on a 2025-code permit, ask them to confirm it with the building department. In the 2025 code, FIDs now appear in a different role, on HRV and ERV ventilation systems.

Federal rules under the AIM Act have been moving new residential air conditioning and heat pump systems away from R-410A to refrigerants with a global warming potential below 700. In practice that means mostly A2L refrigerants such as R-454B and R-32. Under EPA's earlier rules, split systems built from components made before 2025 could only be installed until January 1, 2026. EPA's final rule of May 2026, effective July 27, 2026, removed that installation deadline for systems whose specified components were all made or imported before 2025. California has its own refrigerant rules, so check both before installing leftover inventory.

For California RCV, a few points matter:

• The RA3.2 procedures are not tied to a specific refrigerant. Subcooling and superheat are read with gauges set for the system's refrigerant and compared against the manufacturer's targets. Which method applies depends on the metering device and the manufacturer's instructions, not on the refrigerant, and some systems need an observed weigh-in.
• The winter setup alternative in Appendix RA1.2 lists pressure ranges only for R-410A and R-22. Ask your rater how they handle cold-weather verification on an A2L system.
• A2L refrigerants are mildly flammable, and the equipment comes with its own installation and safety requirements under the mechanical code and the manufacturer's instructions. RCV does not replace those requirements.

Repairing an existing R-410A system is a different situation from installing a new one. Whether a repair triggers RCV depends on which components are replaced, not on the refrigerant type.

The installer adjusts the charge or fixes the fault and the rater re-tests. The failure is recorded in the ECC-Provider's registry even if the problem is corrected on the spot. Ask whether a failed test and return visit cost extra, and have the installer charge the system carefully and document the work first. See typical HERS rater costs.

Search certified raters by city, county or climate zone in the Title 24 Directory. If you work in the Inland Empire, try Riverside County.