R-410A, R-454B and California’s Refrigerant Rules for a 2026 Replacement

Refrigerants

What refrigerant will a new system in Stockton use?

Most new central air conditioners and heat pumps sold in California now use R-454B or R-32 instead of R-410A.

That’s because California and federal rules limit how much a refrigerant can warm the climate, measured as global warming potential (GWP). The California Air Resources Board says new air conditioning equipment must use refrigerants with a GWP below 750. Ducted central AC, heat pumps, mini-splits and packaged rooftop units reached that limit on January 1, 2025. R-410A’s GWP is far above 750.

So when you ask for estimates in 2026, many will quote equipment on a newer refrigerant. Some may still quote R-410A units built before 2025. This guide explains both.

Last updated November 2026.

What are the trade-offs of R-410A versus a newer refrigerant?

It comes down to warranty, matching parts and future service, so ask every contractor the same questions.

Ask each contractor these questions about any R-410A quote:

• When was each piece made, and does it have the full manufacturer warranty?
• Is the outdoor unit matched to a new indoor coil, or to my old one?
• Do you expect service refrigerant prices to change over the life of the system?

And for a quote on R-454B or R-32 equipment:

• Will the line set be replaced or flushed, and is that in the price?
• Does the indoor coil or air handler need to change too?
• Are any safety controls, such as leak sensors, part of the system, and are they included?

What efficiency does a new unit need in California?

Split air conditioners under 45,000 Btu per hour need at least 14.3 SEER2 and 11.7 EER2 in California.

The U.S. Department of Energy’s 2023 standards FAQ explains that California is in the Southwest region, which has stricter rules for split and packaged air conditioners than the North. Split units of 45,000 Btu per hour and up need 13.8 SEER2 and 11.2 EER2. Split heat pumps nationwide need 14.3 SEER2 and 7.5 HSPF2. The DOE says it’s illegal for a contractor to install an air conditioner that doesn’t meet the regional standard.

The EER2 rating matters in Stockton because it measures performance at high outdoor temperatures. NOAA puts the area’s 1% cooling design temperature at 98°F, per its engineering weather data for Stockton Metro Airport.

Are there tax credits or rebates for the new equipment?

Not the federal credit; it covered only equipment placed in service by the end of 2025.

The IRS limits the Energy Efficient Home Improvement Credit to qualifying property placed in service before the end of 2025. California’s main heat pump programs are also tapped out for now. TECH Clean California reports that single-family HEEHRA rebates were fully reserved statewide as of February 24, 2026. If a contractor mentions a rebate, ask which program it is and whether money has been reserved for your job.

Which dates matter?

Five dates explain most of what you’ll hear from contractors in 2026.

What if my current system still works?

Then there’s no rule forcing you to replace it; you can keep repairing it.

The refrigerant rules cover new equipment, not systems already in your home. If your R-410A system runs well, a repair may be the better value, especially when the fault is a small part. Several Stockton reviewers said they were pushed toward a new unit when a capacitor was the real problem, so ask the technician to name the failed part.

It still pays to plan ahead. Find the age on the outdoor unit’s label, note how often it has needed service, and get a replacement estimate before the hottest weeks so you aren’t choosing in a hurry. When the time comes, ask for a quote on newer-refrigerant equipment and, if offered, a quote on pre-2025 stock, so you can compare price, warranty and parts side by side.