Furnace Replacement Cost Calculator
A furnace replacement costs about $4,123 for a standard 80% unit in a basement and $5,917 for a 95% condensing one, on a 2,000 square foot house in Atlanta. The gap is $1,794, and only $670 of it is the furnace. The rest is what a condensing furnace forces: plastic vent through a wall, a condensate drain, and a liner for the chimney your water heater is suddenly using alone.
Estimate the cost for your home
Estimated cost to replace the furnace
$4,177
typical · range $3,021 to $5,334 · 100,000 BTU/h · 80% AFUE · $2,527 of it is the installation
Labour priced at national wages. Enter a ZIP code to price it for your area. 66% of this figure comes from modelled material prices — each line shows its own uncertainty.
Priced from bls.gov Aug 2026how every line is sourced
The one input that changes the answer for you.
The common case, and the one the efficiency rules are written about. A gas furnace burns fuel and vents the products of combustion, which is why where those products go is half of what makes one quote differ from another.
Today's federal minimum for an indoor gas furnace, from 10 CFR 430.32(e). It vents hot through metal pipe and can share an existing masonry chimney. From December 18, 2028 it may no longer be manufactured: the minimum becomes 95%.
The easy case and the baseline for every hour in this model: room to stand, room to swing sheet metal, and a floor drain usually within reach for the condensate.
The cheap, unglamorous, reliable option. It does the one thing that actually saves money — turning the heat down while nobody is home — without needing an app or an account.
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The figure above is already calculated. Each step just makes it more yours, and you can stop at any of them.
The 95% furnace is not a better 80% — it is a different machine
Both figures are your house, your ZIP code and the same working day. The split is what nobody itemises.
| Appliance | Installation | Total | |
|---|---|---|---|
| 80% AFUE | $1,650 | $2,527 | $4,177 |
| 95%+ condensing | $2,320 | $3,668 | $5,988 |
Going condensing costs $1,810 more here, and only $670 of that is the furnace. The other $1,140 is what the furnace forces: plastic vent pipe out through a wall instead of up the chimney, a condensate drain that did not exist before, and a liner for the chimney your water heater is now using alone. If a quote shows you two prices and calls the difference “the high-efficiency option”, this is what is inside it.
And the choice has an expiry date
The federal minimum for an indoor gas furnace is 80% AFUE today and becomes 95% on 18 December 2028, under 10 CFR 430.32(e). That is a manufacturing date, not an installation ban: an 80% furnace built before it stays legal to buy and to fit afterwards. What it does mean is that a furnace bought now will be replaced, eventually, by a condensing one — so the venting work above is not avoided, only postponed. Worth knowing before treating the cheaper option as the settled answer, and worth knowing that nobody selling you either one is likely to bring it up.
| Line item | Qty | Cost | Source |
|---|---|---|---|
| Furnace, 80% AFUEfurnace input BTU ÷ 1,000, when a standard-efficiency gas or propane unit is chosen | 1001,000 BTU/h input | $1,100–$2,200 | estimated±33% |
| Removal, setting and connection16 base trade hours × the access factor for where the furnace sits | 16hour | $913–$980 | sourced |
| Supply plenum and duct transitions1 per replacement | 1each | $180–$420 | estimated±40% |
| Sheet metal fabrication and fitting3 hours × the access factor | 3hour | $171–$184 | sourced |
| Filter cabinet and media filter1 per installation | 1each | $60–$180 | estimated±50% |
| Metal flue connector to the existing chimney1 when a standard-efficiency unit reuses the chimney | 1each | $55–$165 | estimated±50% |
| Gas connection, shutoff and sediment trap1 on any fuel-burning furnace | 1each | $45–$110 | estimated±42% |
| Gas fitting and leak test1.5 hours on any fuel-burning furnace | 1.5hour | $89–$96 | sourced |
| Dedicated circuit, disconnect and service switch1 on any fuel-burning furnace | 1each | $35–$90 | estimated±44% |
| Electrical connection1 hour on a fuel-burning furnace, 5 on an electric one | 1hour | $59–$63 | sourced |
| Thermostat1 unless the existing thermostat is kept | 1each | $35–$240 | estimated±75% |
| Thermostat fitting and configuration0.7 hours for a programmable thermostat, 1.5 for a connected one | 0.7hour | $40–$43 | sourced |
| Old furnace removal and disposal1 when the old unit is taken away | 1each | $45–$120 | estimated±45% |
| Start-up, combustion analysis and airflow check2 hours on a fuel-burning furnace, 1 on an electric one | 2hour | $114–$123 | sourced |
| Mechanical permit and inspection1 when the job is permitted | 1each | $80–$320 | estimated±60% |
| Total | $3,021–$5,334 | ±28% |
Where these numbers come from
- The efficiency floor, and the date it moves
- 10 CFR 430.32(e) sets the minimum Annual Fuel Utilization Efficiency for residential furnaces. For non-weatherized gas furnaces it is 80% today, and for those manufactured on and after December 18, 2028 it becomes 95%. We read that in the regulation itself rather than in a manufacturer’s summary, and it matters because 95% means condensing, and condensing means the venting work priced above. It is a manufacturing date, not an installation ban — but it does mean the cheaper path is a postponement rather than an escape. Retrieved 2026-08-23.
- The chimney nobody mentions until the invoice
- This is the line that catches people. In a great many houses the water heater and the furnace share one masonry chimney. Take the furnace off it and the flue is far too large for the water heater on its own: the exhaust cools on the way up instead of rising, condenses inside the brickwork, and destroys the chimney from the inside while failing to reliably carry combustion products out of the house. The fix is a correctly sized stainless liner, and on this model it is $729 of the condensing option —$5,917 with it against $5,188 without. It is the first question to ask about any high-efficiency quote: what happens to the water heater’s flue.
- Why a furnace is the appliance where the check matters
- A furnace is the one household appliance that makes carbon monoxide by design and relies on being installed correctly to keep it outside. CDC, Carbon Monoxide Poisoning Basics and CPSC, Carbon Monoxide Information Center both cover what that means for a household. The practical version for a replacement: the two hours of start-up and combustion analysis in the breakdown are not padding, the permit inspection is the only independent check the work was done right, and an alarm on every sleeping level is the cheapest line item associated with this job by a wide margin. Both retrieved 2026-08-23.
- Labour rates by area
- BLS Occupational Employment and Wage Statistics, May 2025, for heating and air conditioning mechanics and installers, electricians and pipefitters, adjusted to your metropolitan area. Retrieved 2026-08-20. Benefit load from BLS Employer Costs for Employee Compensation. One piece of good news for once on coverage: heating and air conditioning mechanics are published for 524 of the 530 areas in our index, the best coverage of any specialist trade on this site. The wage is official and regional; the hours are our estimate, and we keep saying which is which.
- Where the furnace sits is a price, not a detail
- The same condensing furnace is $5,917 in a basement and $6,552 in an attic with no gravity drain. Nothing about the appliance changed. What changed is that every tool and both halves of the unit go up a loft ladder, an attic furnace needs a secondary drain pan under it because an overflow up there comes through a ceiling, and the condensate has to be pumped rather than falling. If two quotes on the same house differ and one contractor has been in the attic and the other has not, that is usually the explanation.
- Electric furnaces, and the sentence that decides them
- An electric furnace comes out at $3,498 here against $4,123 for gas: cheaper to install, because there is no flue, no gas connection and no combustion to commission. It is also the most expensive way to heat a house that exists, three to four times the running cost of a heat pump doing the same job. ⚠️ And the figure assumes your panel has both a free double slot and the spare capacity for a 60 to 100 amp feeder. If it does not, the service upgrade can cost as much again, and it is the commonest reason an electric quote lands far above expectation. Before choosing it, price a heat pump against it.
- What the size figure is, and what it is not
- The furnace size here comes from floor area and climate — a screening rule of thumb, not a room-by-room load calculation. On this house it gives 100,000 BTU/h in a mixed climate and 140,000 in a cold one. ⚠️ Rules of thumb like this one systematically come out larger than a real Manual J calculation does, because they are built around the median age of the American housing stock rather than around your house. If yours has been insulated and air-sealed, expect a properly calculated furnace to be smaller — and a smaller furnace is a cheaper furnace that heats more evenly. Manual J is a licensed professional standard and this site does not reproduce it.
- Material prices
- Modelled estimates, not sourced prices. No public, machine-readable source of US residential material prices exists, and we would rather say so than pretend otherwise. Each line carries its own uncertainty band. How we estimate them.
Contractor overhead and profit applied at 33–43% over direct cost. Data last reviewed 2026-08-23.
What this figure does not include
- Oil-fired furnaces
- A different appliance with a tank, a filter, a nozzle and its own service regime. Pricing it inside a gas model would produce a number that is wrong in both directions.
- Ductwork replacement or redesign
- This prices the furnace and the sheet metal immediately around it. If the ducts themselves are undersized or leaking, that is a separate job and often a larger one than the furnace.
- A new gas run from the meter
- Assumes an existing gas line at the appliance. A new run is priced by distance and by what it passes through, and cannot be estimated without seeing it.
- Electrical panel upgrade
- The electric furnace figure assumes the panel has both the physical space and the capacity for a 60 to 100 amp feeder. When it does not, that is a job of its own.
- Asbestos on old duct joints or flue cement
- Houses from before the eighties can have it. It has to be tested rather than disturbed, and abatement is licensed work with its own pricing.
- Air conditioning
- The evaporator coil sits on top of the furnace and is often replaced at the same time, but it is priced on our air conditioner page, not here.
Questions people actually ask
How much does a new furnace cost for a 2000 square foot house?
About $4,123 in Atlanta for a standard 80% gas furnace in a basement, with a range of $2,968 to $5,277, and about $5,917 for a 95% condensing one. A 2,000 square foot house in a mixed climate screens at a 100,000 BTU/h input furnace on this model. Two things move that figure more than the size of the house does: where the furnace sits, because an attic or a crawl space adds up to 40% to the labour, and whether you go condensing, because that changes how the exhaust leaves the building.
How much should it cost to replace your furnace?
On this model, between $2,968 and $8,243 covers most ordinary replacements — the low end being a like-for-like standard-efficiency swap in a basement, the high end a condensing furnace in an attic with a condensate pump. What should worry you is not a number at either end but a quote with one line on it. A furnace replacement has an appliance, sheet metal transitions, a gas connection, a flue, an electrical connection, a thermostat, a permit and a start-up in it. Ask for those separately and the comparison between two quotes becomes possible.
Is it worth replacing a 30 year old furnace?
A 30-year-old furnace is past the point where the arithmetic is close. The trade heuristic people quote is the $5,000 rule: multiply the age in years by the repair quote, and replace if the answer is over 5,000. At 30 years old, any repair over about $167 clears it — a $900 repair gives 27,000. That rule has no official standing and we publish it because it is what people are asking about, not because it is a standard. The stronger argument at that age is different: a heat exchanger that old is the one part whose failure matters, and its failure mode is carbon monoxide.
What is the best month to buy a furnace?
Late spring and early autumn, and the reason is capacity rather than a sale. In a cold snap every heating contractor in the metro is running emergency calls, and a replacement competes with those for the same crew — which shortens the estimate, removes your ability to get three quotes, and puts you in the worst possible negotiating position. Booking a replacement in September for a furnace you already know is failing is worth more than any seasonal discount. This model does not apply a seasonal factor, because we have no measured basis for one.
Taken from Google’s “people also ask” results for this search on 23 August 2026, not invented.
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