A2L refrigerants and R-410A systems
New refrigerant, same question: repair or replace?
New air conditioners and heat pumps are moving to new, mildly flammable refrigerants, and the federal and California rules for an R-410A system don't read the same way. Here's what each says, so a quote doesn't surprise you.
Allowed or not
What you can still do with an R-410A system
EPA's answers first; where California's own rule reads differently, it says so.
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Repairing it
EPA's answer is yes: an existing air conditioning or heat pump system can keep being repaired.
Source: U.S. EPA, Frequent Questions on the Phasedown of Hydrofluorocarbons, checked 2026-10-22.
Allowed
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Filling it with HFC-32 or R-454B
EPA's rules and industry standards prohibit flammable or mildly flammable refrigerants in a system that wasn't designed for them.
Source: U.S. EPA, Frequent Questions on the Phasedown of Hydrofluorocarbons, checked 2026-10-22.
Not allowed
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An old R-22 indoor coil on a new R-410A outdoor unit
The pressures differ, so EPA says the R-22 indoor coil isn't compatible.
Source: U.S. EPA, Frequent Questions on the Phasedown of Hydrofluorocarbons, checked 2026-10-22.
Won't work
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Replacing the outdoor unit and the indoor coil together
Change both at once and EPA counts it as installing a new system.
Source: U.S. EPA, Frequent Questions on the Phasedown of Hydrofluorocarbons, checked 2026-10-22.
New system
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A new outdoor unit on its own
California's rule counts an existing single split system that gets a new outdoor condensing unit as new air-conditioning equipment, so ask how the replacement meets the state's limit.
Source: California Air Resources Board, Final Regulation Order: Prohibitions on Use of Certain Hydrofluorocarbons (2020), checked 2026-10-22.
Ask first
California's limit on new equipment
New air conditioners, heat pumps and VRF systems for California homes and businesses must use a refrigerant with a GWP less than 750, a limit that phases in by equipment category.
Since January 1, 2026, a heat pump or air conditioner has also needed a refrigerant with a GWP of 700 or lower to qualify for California's HEEHRA rebate, though that money is now fully reserved.
Source: California Air Resources Board, air-conditioning equipment rules. Rules and programs change: last checked 2026-10-17.
Source: California Energy Commission, Inflation Reduction Act Residential Energy Rebate Programs. Rules and programs change: last checked 2026-10-22.
The federal rule
EPA's latest rule lets pre-2025 inventory of air conditioning systems be installed until it runs out, and sets no installation deadline for a system whose specified components were all made or imported before January 1, 2025.
EPA also warns that R-410A and the parts for it may get harder to find as HFCs are phased down. In California, ask how a quote's system meets the state's own rule before you sign.
Source: U.S. EPA, Fact Sheet: Technology Transitions Reconsideration Final Rule (May 2026). Rules and programs change: last checked 2026-10-22.
Source: U.S. EPA, Technology Transitions HFC Restrictions by Sector. Rules and programs change: last checked 2026-10-22.
Source: U.S. EPA, Frequent Questions on the Phasedown of Hydrofluorocarbons. Rules and programs change: last checked 2026-10-22.
Ask which refrigerant a quote is for
A quote for a new system should name its refrigerant. If it names R-410A, ask how it meets California's rule, and get the answer in writing.
Tell us what it's doing. We'll take it from there.
Call and describe the problem: the noise, the smell, the room that never warms up. Or book a visit online.
