HVAC · gas furnace
Gas furnace replacement cost
An 80,000 BTU/h gas furnace at AFUE 0.90 has a certified national retrofit benchmark of $3,566.89 (2023 USD) low, $3,846.25 (2023 USD) typical, and $4,568.02 (2023 USD) high.
Source year. Based on NREL REMDB Gas Furnace in 2023 dollars.
Geographic scope. United States national modelled benchmark.
Model scope. Gas furnace retrofit. Heating capacity 30,000–156,250 BTU/h. AFUE 0.80–0.97 as a decimal, not a percent.
Important limitation. Entering AFUE as 90 instead of 0.90 is outside the workbook and fail-closes. This is not an air-conditioner or heat-pump price.
Certified benchmark values
| Band | Value |
|---|---|
| installed low | $3,566.89 (2023 USD) |
| installed typical | $3,846.25 (2023 USD) |
| installed high | $4,568.02 (2023 USD) |
Benchmark estimator
Results are modelled 2023 USD benchmarks, not a contractor quote.
Modelled benchmark: Low $3,566.89 (2023 USD); typical $3,846.25 (2023 USD); high $4,568.02 (2023 USD)
Formula: retail=0.00645*m1(80000)+4325.000025*m2(0.9)+-2780.000019; installed=retail*1+2217.753. This modelled range is not a contractor quotation.
Typical result $3,846.25 (2023 USD)
What this estimate includes
- BTU/h and AFUE regression
- Gas furnace retrofit adder
What moves the number
- Heating capacity
- AFUE decimal
- Cooling equipment, which is not in this total
Methodology and sources
- 80,000 BTU/h is inside the published domain, not a RECS typical furnace.
- No package discount with central air is applied.
Primary source: National Residential Efficiency Measures Database 2024.
How to use this result when planning
- Enter AFUE as a decimal. 0.90 is in-domain. 90 is outside the workbook and fail-closes.
- Certified heating capacity is 30,000–156,250 BTU/h. The default point is 80,000 BTU/h at AFUE 0.90.
- This total is a gas furnace only. It does not add a matching air conditioner.
Same AFUE, smaller in-domain furnace
Keep AFUE 0.90. Change only capacity from 80,000 to 60,000 BTU/h.
Engine result: Low $3,472.01 (2023 USD); typical $3,717.25 (2023 USD); high $4,347.02 (2023 USD). Formula: retail=0.00645*m1(60000)+4325.000025*m2(0.9)+-2780.000019; installed=retail*1+2217.753. This modelled range is not a contractor quotation.
When to get a contractor quotation
- Get a quote after a heat-loss calculation, not from the existing furnace nameplate alone.
- Ask whether the bid includes flue, condensate, and gas-line work. Those items are not split out of the REMDB adder.
Limitations
- 2023$ historical REMDB retrofit benchmark, not a 2026 contractor quote.
- REMDB may include upstream RSMeans/retail-derived inputs; cite REMDB only.
- Gas furnace. AFUE is a decimal (0.80–0.97). 80,000 BTU/h is in-domain, not a RECS typical.
Questions this evidence can answer
Should I type 90 for a 90% furnace?
No. The certified bounds are 0.80 to 0.97. A value of 90 is rejected.