140,000 BTU Gas Furnaces: What to Know Before You Buy
A 140,000 BTU furnace is one of the largest home sizes, for a big house in a cold climate. Most homes need far less, so ask for the heat-loss calculation (Manual J) before you accept a quote. We found none on Amazon at this size; an installer supplies it. You can buy its filter and thermostat yourself, below.
Is 140,000 BTU the right size?
The 140,000 is the input: the gas the furnace burns per hour. The heat it delivers is the input times its AFUE, so a 96% AFUE unit delivers about 134,400 BTU and an 80% unit 112,000.
Replacing a furnace? The old one may have been oversized. The U.S. Department of Energy recommends sizing by a contractor's load calculation, not by the old unit or the square footage.
What it costs
| Furnace | Typical installed price |
|---|---|
| 80% AFUE, single-stage | $3,800 to $6,200 |
| 90–96% AFUE, condensing | $5,200 to $8,800 |
| 96%+ AFUE, modulating | $7,500 to $12,000 |
U.S. typical installed price for a like-for-like replacement, equipment, labor and permit together, from published 2026 data (compiled July 2026). Price tracks efficiency more than size.
Questions buyers ask
- How many square feet does a 140,000 BTU furnace heat?
- It depends on your climate and insulation far more than the floor area. A contractor's heat-loss calculation (Manual J) gives the answer; most homes, even large ones, need less than 140,000 BTU.
- Can I buy a 140,000 BTU furnace online?
- We found none on Amazon. Installers supply furnaces this size. You can buy the filter and a smart thermostat yourself.
- Should I buy an 80% or a 96% AFUE furnace?
- At 96% AFUE, 96 cents of every gas dollar becomes heat in your home; at 80%, 80 cents. The gap matters most in a cold climate, where a furnace this size runs the most.
Every certified 140,000 BTU furnace (238)
The furnaces below are certified at this input rating, ranked by AFUE, and sold through installers. If an installer quotes one, find it here to check its efficiency. The table shows the 20 with the highest AFUE; the full product list has all 238.
The 20 highest-AFUE of 238 certified units
| Brand & model | AFUE | Input | Fuel | $/MMBtu | Buy | |
|---|---|---|---|---|---|---|
| LENNOX SLP99UH135XV60D | 98.4 | 132,000 BTU | Natural Gas, Propane Gas | $17.07 | installer | |
| GE NF98U135M5DR | 98.0 | 132,000 BTU | Natural Gas, Propane Gas | $17.14 | installer | |
| AIREASE A98USMV135D20S | 98.0 | 132,000 BTU | Natural Gas, Propane Gas | $17.14 | installer | |
| LENNOX ML297UH135XV60D | 97.0 | 132,000 BTU | Natural Gas, Propane Gas | $17.32 | installer | |
| GE NF97U135T5DR | 97.0 | 132,000 BTU | Natural Gas, Propane Gas | $17.32 | installer | |
| KEPLER 97G2UH135DV20 | 97.0 | 132,000 BTU | Natural Gas, Propane Gas | $17.32 | installer | |
| GE NF97U135V5DR | 97.0 | 132,000 BTU | Natural Gas, Propane Gas | $17.32 | installer | |
| COMFORT-AIRE GUH97T135D5MP | 97.0 | 132,000 BTU | Natural Gas, Propane Gas | $17.32 | installer | |
| AIREASE A97US2V135D20S | 97.0 | 132,000 BTU | Natural Gas, Propane Gas | $17.32 | installer | |
| LENNOX EL297UH135XE60D | 97.0 | 132,000 BTU | Natural Gas, Propane Gas | $17.32 | installer | |
| LENNOX EL297UH135XV60D | 97.0 | 132,000 BTU | Natural Gas, Propane Gas | $17.32 | installer | |
| KEPLER 96G1UH135DE20 | 96.0 | 132,000 BTU | Natural Gas, Propane Gas | $17.50 | installer | |
| GE NF96U135S5DR | 96.0 | 132,000 BTU | Natural Gas, Propane Gas | $17.50 | installer | |
| COMFORT-AIRE GUH96C135D5MP | 96.0 | 132,000 BTU | Natural Gas, Propane Gas | $17.50 | installer | |
| PHANTOM B96UR1351E5D | 96.0 | 132,000 BTU | Natural Gas, Propane Gas | $17.50 | installer | |
| AIREASE A96UH1E135D20S | 96.0 | 132,000 BTU | Natural Gas, Propane Gas | $17.50 | installer | |
| LENNOX ML196UH135XE60D | 96.0 | 132,000 BTU | Natural Gas, Propane Gas | $17.50 | installer | |
| ACIQ N96MSN1402422A | 95.0 | 140,000 BTU | Natural Gas, Propane Gas | $17.68 | installer | |
| WEATHERMAKER PG96MSAA66140D | 95.0 | 140,000 BTU | Natural Gas, Propane Gas | $17.68 | installer | |
| BRYANT 916SA66140M24 | 95.0 | 140,000 BTU | Natural Gas, Propane Gas | $17.68 | installer |
Capacity and efficiency are AHRI-certified values; $/MMBtu is computed by us from EIA energy prices — see methodology. Input rating is the fuel the burner consumes; the heat delivered is lower, by about the AFUE.