From December 18, 2028, every residential gas furnace manufactured in the US must reach at least 95% AFUE. That effectively ends production of the non-condensing 80% units that have been the default budget option for decades.
Predictably, this has generated a lot of "buy one before they're banned" advice. For most households that advice is wrong, and the reason is straightforward arithmetic. Here's what the rule actually says and what it means for your next furnace.
What the Rule Does and Doesn't Do
Three things get muddled constantly in coverage of this:
- It applies to manufacture, not ownership. Nobody has to replace a working furnace. There's no inspection, no deadline attached to your house, and no requirement triggered by selling a home.
- It applies to the manufacturing date, not the sale date. Distributors can keep selling 80% inventory made before the cutoff, with no sell-through deadline. Availability will taper over the following months rather than vanishing on the day.
- Repairs are unaffected. Parts for existing furnaces don't fall under an efficiency standard for new equipment.
DOE upheld the standard in late 2025 after a legal challenge. Since then, separate legislation to overhaul how appliance standards are set has been introduced in Congress, so the picture could shift before 2028 — worth checking the current status if your decision depends on the date.
Why "Buy Cheap Before the Ban" Usually Loses
The pitch is that you save $800–1,500 by getting a non-condensing unit while you still can. The part that gets left out is what that costs you afterwards.
Going from 80% to 95% AFUE cuts gas consumption by 15.8% — not 15 percentage points, but the ratio 1 − (0.80 ÷ 0.95). For a household burning 700 therms a year at $1.70/therm, that's about $188 a year, every year, for the 15–20 year life of the equipment.
Run that against a $1,200 premium over 18 years with modest gas price escalation and the condensing unit finishes roughly $3,200 ahead, paying back the premium in about six years. You can put your own consumption and quotes into our furnace AFUE upgrade calculator, which also tells you the break-even premium — the venting cost above which the cheaper unit actually would win.
The Venting Retrofit Is the Real Cost
The equipment price gap between 80% and 95% furnaces is smaller than most people assume. The bulk of the difference is installation, driven by a physical constraint:
A condensing furnace pulls so much heat out of the combustion gases that the exhaust comes out cool and wet. Cool flue gas won't rise up a chimney by itself, and the condensed moisture is mildly acidic — it damages masonry and metal flues. So condensing units use a fan to push exhaust through PVC pipe out a sidewall, and need a condensate drain, plus a condensate pump if there's no gravity drain within reach.
That makes the premium highly house-specific. A basement furnace near a floor drain and an exterior wall is the cheap case. An attic or interior-closet installation is the expensive one. Get it as an itemised line on your quotes rather than accepting a lump sum.
One knock-on effect worth raising with your installer: if your water heater currently shares a chimney with the furnace, pulling the furnace off that flue can leave it oversized for the water heater alone, which causes draft and condensation problems. Good installers flag this unprompted; not all do.
Why the Official Savings Figure Looks Small
DOE describes the rule as saving about $350 over a furnace's lifetime, or up to $50 a year. If you ran the calculator and got several times that, both figures can be correct.
The DOE number is a national average, net of the higher purchase price. It blends in households in mild climates that barely run a furnace, and accounts for the roughly one in twenty households expected to install a heat pump instead of a condensing furnace. A cold-climate household burning 900+ therms is nowhere near that average.
This is a general hazard with appliance standards coverage: the headline figures are population averages, and the spread between a Houston household and a Minneapolis one is enormous. Your own gas bill is a far better guide than any national number.
The Policy Argument, Briefly
There's a genuine dispute here and it's worth stating both sides rather than picking one.
Efficiency advocates and DOE point to lifetime bill savings and emissions reductions, and note that appliance standards have broad public support — a 2025 Consumer Reports survey found 87% of US adults agreed new appliances should meet a minimum efficiency level. DOE has separately estimated its furnace standard would avoid substantial CO₂ emissions over 30 years.
Gas industry groups and some manufacturers argue the standards raise equipment costs and narrow choice, particularly for homes where the venting retrofit is expensive, and that the burden falls hardest on households least able to absorb an unexpected replacement cost. A related rule on gas tankless water heaters was repealed via the Congressional Review Act in May 2025, and DOE has proposed withdrawing a broader slate of standards since.
Both positions contain something true. Which matters more to you depends on your gas consumption and your house — which is exactly why an individual calculation beats a national talking point.
The Option This Debate Skips
If your furnace is near end of life, 80%-versus-95% isn't the only question. A heat pump replaces the furnace entirely and provides cooling too.
The economics moved at the end of 2025 when the 30% federal credit expired. At the 2026 national average — about 18.4¢/kWh and $1.70/therm — a heat pump at COP 3.0 and a 95% gas furnace land close to even on running cost, so the decision turns on your local rates, how cold your winters get, and whether you need to replace an air conditioner anyway.
Our heat pump economics without the tax credit covers where that stands now, heat pump vs furnace vs boiler compares running costs across all three, and the heating cost by fuel calculator puts every fuel on the same per-BTU basis.
The Bottom Line
If your furnace works, do nothing — the rule doesn't touch you. If it's failing, run your own numbers rather than acting on the deadline: for most households the condensing unit wins comfortably, but a mild climate or an awkward venting situation can flip it, and that's worth knowing before you sign a quote.