Last reviewed: September 2026 · By the HVAC Brief Editorial Team · Our sourcing and editorial standards
Central heating is any system that produces heat in one place and distributes it through the house, by ducts or by pipes. In the US it usually means a forced-air furnace: 74.42 million homes, 63.2% of those that heat, use a central warm-air furnace as their main heating equipment, according to EIA’s Residential Energy Consumption Survey.
Add central heat pumps and 90.55 million homes, 76.9%, heat with ducted forced air. Boilers feeding radiators or radiant floors, which is what central heating usually means in Britain, are the main system in 9.29 million.
How forced-air central heating works
A furnace heats air and a blower pushes that air through ducts. The flame or element never touches the air you breathe; a heat exchanger sits between them.
- The thermostat calls for heat.
- The furnace produces heat, by burning gas, propane or oil, or by passing current through electric resistance elements.
- A heat exchanger transfers that heat to the air while keeping combustion gases in a separate path.
- The blower pushes warmed air into the supply ducts and out through registers in each room.
- Return ducts draw cooler room air back to the furnace, through the filter, to be heated again.
- Combustion gases vent outdoors through a flue or, on high-efficiency condensing furnaces, through plastic vent pipe.
A heat pump does the same distribution job but moves heat from outdoor air instead of making it. See heat pump versus gas furnace.
What US homes heat with
Forced air dominates. The central furnace alone is the main system in more homes than every other type of heating equipment combined.
| Main heating equipment | Homes (millions) | Share of homes that heat |
|---|---|---|
| Central warm-air furnace | 74.42 | 63.2% |
| Heat pump | 16.13 | 13.7% |
| Steam or hot water system | 9.29 | 7.9% |
| Built-in electric units | 7.65 | 6.5% |
| Built-in oil or gas room heater | 3.49 | 3.0% |
| Portable electric heaters | 3.03 | 2.6% |
| Wood-burning stove | 1.94 | 1.6% |
| Ductless heat pump (mini-split) | 1.06 | 0.9% |
| Some other equipment | 0.74 | 0.6% |
| Homes using heating equipment | 117.74 | 100% |
Figures are EIA RECS 2020, table HC6.1, and may not sum exactly because of rounding. Fuel shares across all equipment types are covered in how American homes are heated.
Does central heating use gas?
Usually, but not always. Of the 74.42 million homes heating mainly with a central furnace, 71.6% burn natural gas.
| Furnace fuel | Homes (millions) | Share of furnace homes |
|---|---|---|
| Natural gas | 53.26 | 71.6% |
| Electricity | 13.82 | 18.6% |
| Propane | 4.03 | 5.4% |
| Fuel oil or kerosene | 3.10 | 4.2% |
Electric furnaces are the second largest group. They have no flame and no flue, and they convert electricity to heat one for one, which makes them expensive to run where electricity is expensive.
Forced air versus hot water
Both are central heating. The difference is what carries the heat: air through ducts, or water through pipes to radiators, baseboards or floors.
| Factor | Forced air | Hot water (hydronic) |
|---|---|---|
| Heat carrier | Air, through ducts | Water, through pipes |
| Shares ducts with central air | Yes | No, cooling needs a separate system |
| Filtration and humidity control | Built into the air path | Not part of the system |
| Federal efficiency metric | AFUE for furnaces, HSPF2 for heat pumps | AFUE for boilers |
| Homes using as main heat | 90.55M with heat pumps | 9.29M |
More on the water side in radiant floor heating.
Federal efficiency minimums for furnaces
A new non-weatherized gas furnace must reach 80% AFUE today, and 95% for units manufactured from December 18, 2028, under 10 CFR 430.32(e).
| Furnace class | Current minimum AFUE | From December 18, 2028 |
|---|---|---|
| Non-weatherized gas furnace | 80.0% | 95.0% |
| Mobile home gas furnace | 80.0% | 95.0% |
| Weatherized (outdoor) gas furnace | 81.0% | No change scheduled |
| Non-weatherized oil-fired furnace | 83.0% | No change scheduled |
| Weatherized oil-fired furnace | 78.0% | No change scheduled |
| Mobile home oil-fired furnace | 75.0% | No change scheduled |
| Electric furnace | 78.0% | No change scheduled |
AFUE is determined under the federal test procedure, so these are rating floors rather than measured performance in a given house. The 2028 change and what it means for venting is covered in the 95% furnace standard.
What central heat costs to run, by fuel
At 2025/26 heating season average prices, heat from an 80% gas furnace cost about $18.81 per million Btu delivered, against $52.10 from an electric furnace and $23.70 from a minimum-efficiency heat pump.
The full comparison, including propane, oil and the prices used, is in what heat costs by fuel.
How old heating systems are
Heating equipment is kept much longer than cooling equipment. 20.0% of homes that heat run main heating equipment 20 years old or more, against 9.6% of air conditioned homes for cooling equipment.
| Age of main heating equipment | Homes (millions) | Share of homes that heat |
|---|---|---|
| Less than 2 years | 13.29 | 11.3% |
| 2 to 4 years | 17.19 | 14.6% |
| 5 to 9 years | 26.77 | 22.7% |
| 10 to 14 years | 22.29 | 18.9% |
| 15 to 19 years | 14.66 | 12.5% |
| 20 years or more | 23.54 | 20.0% |
Ages are reported by households, grouped in bands, and cover all main heating equipment, including long-lived boilers.
Frequently asked questions
What is central heating?
A system that produces heat in one place and distributes it through the whole house, either as warm air through ducts or as hot water through pipes. In the US the most common form is a forced-air furnace, the main heating equipment in 74.42 million homes, per EIA RECS 2020.
Does central heating use gas?
Most often. Of 74.42 million homes heating mainly with a central furnace, 53.26 million, 71.6%, use natural gas. The rest use electricity, propane or fuel oil. Central heat pumps and electric furnaces use no gas at all.
What is forced air heating?
Heating that warms air in a furnace or heat pump and pushes it through ducts with a blower. Furnaces and central heat pumps together are the main heating system in 90.55 million US homes, 76.9% of homes that use heating equipment.
What is the most common heating system in the US?
The central warm-air furnace, the main heating equipment in 74.42 million homes, 63.2% of those using heating. Heat pumps are second at 16.13 million and steam or hot water systems third at 9.29 million, per EIA RECS 2020.
Methodology and limitations
Household counts and ages are EIA RECS 2020, table HC6.1. Efficiency minimums are quoted from 10 CFR 430.32(e). Running costs use EIA season average prices and federal minimum efficiencies, as documented on our fuel cost page.
- RECS 2020 is a survey estimate and the latest vintage for equipment data, with the 2024 survey’s equipment tables due in spring 2027 See what the 2024 survey release covers.; we do not project it forward.
- Furnace fuel rows do not sum to the furnace total because of rounding and suppressed cells.
- We publish no installed prices, because no federal series measures them.
Sources
- US Energy Information Administration, Residential Energy Consumption Survey 2020, table HC6.1.
- Code of Federal Regulations, 10 CFR 430.32(e), furnace and boiler standards.
The HVAC Brief is an independent trade publication. We do not sell equipment, take manufacturer advertising, or accept payment for placement in our research. Corrections welcome.
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