The last two years brought real changes to heating and air conditioning — new refrigerants, shifting federal rules and the end of a popular tax credit. Here's a plain-language rundown of what's changed and what it means if you own a home in Columbia or the Midlands. Updated September 2026.
1. New systems use new refrigerants — your old one isn't illegal
Under the federal AIM Act, the EPA is phasing down HFC refrigerants like R-410A. Since January 1, 2025, new residential split-system air conditioners and heat pumps have been made for lower-impact refrigerants, mainly R-32 or R-454B.
What that does not mean: your existing R-410A system is still legal to own, run and repair. The new refrigerants aren't drop-in replacements for R-410A, so never let anyone "convert" your system with a different refrigerant. For the details, see our R-410A guide.
2. The EPA dropped the R-410A installation deadline
The original rules would have stopped contractors from installing any leftover R-410A split systems after January 1, 2026. In a final rule published May 26, 2026 (effective July 27, 2026), the EPA removed that deadline for residential and light-commercial split systems whose components were made or imported before January 1, 2025. So you may still see some R-410A equipment offered alongside the newer R-32 and R-454B systems. Ask which refrigerant a proposed system uses — it affects future service costs.
3. The federal heat pump tax credit is gone
The Section 25C Energy Efficient Home Improvement Credit — up to $2,000 for a qualifying heat pump — ended for equipment placed in service after December 31, 2025. If a contractor promises you that credit for a 2026 installation, that's a red flag. If your system was installed and running by December 31, 2025, you could claim it on your 2025 return.
South Carolina's federally funded HOMES and HEAR home energy rebates had not launched as of this update. Check the SC Energy Office rebates page for the latest.
4. Local utility rebates still help
If you're a Dominion Energy South Carolina residential electric customer, you may qualify for rebates when a licensed contractor installs qualifying ENERGY STAR equipment. Dominion's current published programs include rebates toward new central air conditioners and heat pumps, a larger rebate for replacing an all-electric furnace with a heat pump, and a rebate for replacing an electric water heater with a heat pump water heater. Amounts and rules change, so check Dominion Energy's heating and cooling rebates before you buy. Applications are generally due within 90 days of installation.
5. Variable-speed and smarter controls are more common
More systems now use variable-speed or inverter-driven compressors that adjust output instead of running full-blast. In a humid climate like ours, that can mean steadier temperatures and better moisture removal — when the system is sized and installed correctly. Smart and communicating thermostats are more common too, but compatibility varies, so check before you buy one. Our smart thermostat guide explains what to look for.
What this means for you
Don't replace a working system just because it uses R-410A.
If you need a repair, get an honest diagnosis and prices for both repair and replacement.
If you're replacing, ask which refrigerant the new system uses and whether the indoor and outdoor units are an approved match.
Don't count on the federal tax credit for 2026 — check Dominion Energy rebates instead.
Consider ductwork, insulation and air sealing alongside new equipment. For additions and rooms without ducts, look at ductless mini-splits.
Have questions about your system? On Call's NATE-certified technicians have served Columbia and the Midlands since 2011, and we install primarily Trane. Our residential diagnostic fee is $89, waived when you go ahead with the repair, and you'll get a firm price on site before any work begins. Replacing your system? Ask about financing — your technician can walk you through the options in person. Call (803) 781-4357 or request service online.
