By Robert Patterson · Reviewed by Robert Patterson, TDLR-licensed · Last updated Jul 23, 2026
The short answer: the biggest 2025 change is the refrigerant transition to A2L (R-454B), which changes the equipment and the safe-install practices behind a code-compliant job. For homeowners it mostly means: use a properly trained, licensed installer.
What changed?
Under the EPA's phase-down, new residential systems moved from R-410A to lower-GWP A2L refrigerant (R-454B) in 2025 — the full story is in our A2L explainer. A2L is mildly flammable, so leak detection, disconnect, and handling requirements are stricter.
How it affects a permitted install
A code-compliant A2L change-out means the right equipment, correct line-set handling, and installer certification — exactly the kind of work an inspection on a mechanical permit is meant to verify. See HVAC permits in our counties.
What it means for your next system
You don't need to rush to replace a working R-410A system — keep maintaining it. But a new AC or heat pump today will be A2L, so the installer's training matters more than ever. Our technicians are TDLR-licensed and EPA-certified.
Your next step
Have questions about A2L or code on your upcoming project? Ask us — no pressure, honest answers. Explore A2L-ready brands or the Learning Center.
General information, not legal or code advice. Codes and refrigerant regulations change and vary by jurisdiction — confirm current rules with your local AHJ. Reviewed by Robert Patterson, TDLR-licensed, July 2026.