No, you should not use R-410A in an R-454B system. While the system might physically run, it is prohibited, unsafe, and will damage the equipment.
No, R-454B is not a drop-in replacement for R-410A. You cannot retrofit or mix them in the same system.
The only non-flammable "drop-in" (retrofit) replacement for R410A in existing HVAC systems is R-470A (sold by ComStar under the name RS-53). It drops into existing R410A systems with a roughly 56% lower Global Warming Potential (GWP) and requires no oil or component changes.
Con: R-454B is mildly more flammable
In fact, all refrigerants are. But R-454B is classified as having an A2L rating, while R-410A is classified as having an A1 rating. However, this shouldn't scare you. It's still only mildly flammable, and as long as it's handled correctly, it's perfectly safe.
R-454B is NOT a drop-in replacement for R-410A. Although many of the characteristics of R-454B are similar to R-410A, the use of R-454B is restricted by code and regulation to systems for which it was specifically designed.
January 1, 2025: Manufacturers stopped producing new R-410A residential split systems and heat pumps. Equipment manufactured before this date can still be sold and installed. January 1, 2026: The original deadline for installing R-410A split systems manufactured before 2025.
For those seeking to install R-454B equipment, the height of the shortage may have passed. Data on R-454B prices and information from manufacturers suggest that the supply chain issues were resolving as of August 2025. In August, prices for R-454B from online retailers were 50-60% lower than the prices in June.
R-410A is currently being phased down rather than fully banned, with the production of new R-410A equipment already banned. The remaining supply will be gradually reduced by 85% through 2036.
R-454B shows 98 % capacity and 102 % efficiency compared to R-410A at rating conditions of 35 °C outdoors and water return temperature of 12 °C.
R-454B is incredibly expensive due to a sudden, concentrated industry shift to the new A2L refrigerant, combined with heavy import tariffs and a severe shortage of specialized, safety-rated cylinders.
Any Carrier HVAC systems installed moving forward will use Puron Advance refrigerant instead of R-410A.
R-454B (often marketed as Puron Advance™) is a mildly flammable (A2L) refrigerant designed to replace R-410A. It operates at slightly higher pressures than R-410A, with average suction pressures ranging from 80 to 150 psig and high-side condensing pressures commonly hitting 480 to 560 psig depending on ambient temperatures.
Replacement Refrigerants
R-454B and R-32 are the two refrigerant that's most likely to replace R-410a.
Yes, you can generally reuse existing R-410A copper line sets for R-454B systems, provided they are in good condition, properly sized, and thoroughly flushed to remove old oil. While R-454B (an A2L "mildly flammable" refrigerant) has different properties, it is compatible with the POE oil and copper tubing used in R-410A systems.
Yes, you can still buy R-410A equipment today, but only as remaining overstock. The manufacture of new residential R-410A systems is prohibited, but residual stock legally remaining in distributor warehouses can still be sold and installed.
As of January 1, 2020, the United States banned the use of the R22 refrigerant, commonly known as Freon.
No, you cannot top off R-454B with R-410A.
Yes – Eligible R410A Systems Can Still Be Installed in 2026
Short answer: Yes. Eligible R410A systems manufactured before January 1, 2025, can still be installed in 2026 under the Technology Transitions Rule issued by the U.S. Environmental Protection Agency.
R454B refrigerant
This refrigerant is based on HFO technology and boasts a low GWP of 465, with CO2 emissions 78% lower than R410A and 31% lower than R32.
A2L refrigerants, the new refrigerants for 2026, will replace R-410A in new systems. A lot about A2L refrigerants is explained in their name: The “A” means low toxicity. The “2L” is a safety classification, indicating it is mildly flammable.
Many Amish homes are built with plenty of windows to help circulate the air and bring in the cooler overnight temperatures. They open the windows on the top floors to help the heat escape while the family retreats to the lower grounds within their homes for comfort.
The primary replacements for R-410A in new HVAC systems are R-32 and R-454B. Both are environmentally friendly "A2L" (mildly flammable) refrigerants. Because of this classification, R-410A cannot be directly substituted with these new gases; entirely new equipment designed for safety and handling is required.
Yes HVAC prices have steadily increased over the past few years, and 2026 is no exception. These increases are affecting everything from entry-level systems to high-efficiency units, making it more expensive than ever to install or replace HVAC systems.
Most major HVAC manufacturers in the United States have adopted R-454B (sold by brands like Chemours as Opteon™ XL41 and by Carrier as Puron Advance™) as their primary replacement for R-410A.
Trane is phasing in the transition to R-454B in 2024, starting with the adoption of R-454B refrigerant in its residential products, beginning with the XR15 SEER2 heat pump.