Heat Pump vs. Gas Boiler/Furnace Calculator
Compare modeled 20-year heat-pump and gas-system costs under your entered assumptions. Uses stored state-average gas and electricity prices and estimates annual CO₂ change. No federal credit or state rebate is subtracted automatically.
Standard split-system, works to ~5°F, most common choice
Standard efficiency gas furnace
Federal 25C Heat Pump Credit — Expired Dec 31, 2025
The federal 25C heat pump credit expired December 31, 2025. It is not available for 2026+ installations. If your system was installed in 2025, you may still claim up to $2,000 on your 2025 tax return. State HEEHRA rebates may still apply depending on your state and income — check your state energy office.
Figures below reflect 2026 installs with no federal 25C credit applied. If you installed in 2025, subtract your eligible credit from the net cost. Always consult a tax professional.
How this comparison works
1. Heating demand. Annual heat = design heating load (BTU/hr) × annual heating hours. The defaults, 30,000 BTU/hr and 1,400 hours, give 42.0 million BTU. Replace them with figures from a load calculation or your bills when you have them.
2. Heat pump electricity. kWh = heat ÷ 3,412 BTU/kWh ÷ seasonal COP, where COP = HSPF2 ÷ 3.412. A standard air-source unit rated HSPF2 9 has a seasonal COP of about 2.64, so it needs about 4,667 kWh for heating.
3. Gas. Therms = heat ÷ AFUE ÷ 100,000 BTU/therm. An 80% AFUE furnace needs about 525 therms.
4. Cooling. Size is estimated at one ton per 400 sq ft (minimum one ton), run for your cooling hours. The heat pump cools at its SEER2 rating; a furnace is paired with a separate 14 SEER central air conditioner whose $4,200 installation is added to the gas side (not for boilers). At 2,000 sq ft that is 5 tons: about 3,048 kWh for the heat pump versus 3,918 kWh for the air conditioner.
Worked example (defaults, stored national averages of 18.34¢/kWh and $1.58/therm). Including fixed maintenance assumptions ($150 a year for the heat pump, $250 for furnace plus AC), the heat pump costs about $1,565 a year and the gas system about $1,798. Planning installation costs are $7,500 for the heat pump and $8,400 for the furnace with AC. Results change sharply with local prices: where electricity is expensive relative to gas, the heat pump can cost more to run.
What this model leaves out. HSPF2 is a seasonal rating for a reference climate; real COP drops in colder weather, so results in cold regions can be optimistic unless you use a cold-climate model and a lower effective COP. The one-ton-per-400-sq-ft rule is a rough simplification. Equipment, maintenance, and installation figures are planning assumptions, ductwork and electrical upgrades are not included, and no rebate is subtracted. CO₂ uses 11.7 lb per therm for gas and the EPA eGRID2023 U.S. average of 0.7715 lb per kWh, counting cooling electricity on both sides.
Frequently Asked Questions
Can a heat pump fully replace my gas furnace?
In many US climates, yes, if the system is sized from a room-by-room load calculation (ACCA Manual J). Many cold-climate air-source models are rated to keep operating at outdoor temperatures down to about -13°F, but their capacity and efficiency fall as it gets colder; ENERGY STAR's cold-climate criteria require a COP of at least 1.75 at 5°F. In very cold regions, designers often add electric-resistance backup or keep a furnace as dual-fuel backup for the coldest hours.
What was the IRA 25C credit for heat pumps?
The IRA Section 25C heat pump tax credit expired December 31, 2025. It previously provided a 30% federal tax credit (non-refundable) for qualifying heat pumps, up to $2,000 per year. If you installed a qualifying heat pump in 2025, you may still claim this credit on your 2025 tax return.
Do I need to upgrade my electrical panel for a heat pump?
Panel capacity depends on the home's existing loads and the selected equipment; a licensed electrician should assess it. A panel upgrade qualified for a $600 Section 25C credit only when installed with qualifying property placed in service by December 31, 2025; that credit has expired. HEAR panel-upgrade rebates (up to $4,000, income-qualified) may apply in states whose Home Energy Rebate program is open and funded. This calculator applies no federal 25C credit to a 2026 installation.
How does cooling efficiency factor into the comparison?
Heat pumps provide both heating and cooling in one system. A gas furnace must be paired with a separate central air conditioner. This calculator includes the estimated AC installation cost and cooling energy in the gas system total.