Gas Furnace vs Electric Furnace: Which Is Better for Your Home?

Gas Furnace vs Electric Furnace at a Glance

What Is a Gas Furnace?

A gas furnace is a forced-air heating system that uses natural gas or propane
as its primary fuel.

The furnace burns fuel inside a burner assembly. Heat from combustion is
transferred through a heat exchanger to the household air. A blower then
distributes that warmed air through the home’s ductwork.

The combustion gases do not normally enter the home’s air distribution system.
They are exhausted through a properly designed venting system.

Gas furnaces are commonly rated using AFUE, or Annual Fuel Utilization
Efficiency. AFUE represents the percentage of fuel energy converted
into useful space heating over the heating season. 1

Modern high-efficiency gas furnaces can achieve AFUE ratings in the upper 90%
range. ENERGY STAR currently specifies at least 95% AFUE for qualifying gas
furnaces in its U.S. South region and 97% AFUE in its U.S. North region.
2

What Is an Electric Furnace?

An electric furnace is also a forced-air heating system, but instead of burning
fuel it uses electrical resistance heating elements.

When electricity flows through the heating elements, electrical resistance
generates heat. A blower moves air across the elements and distributes the
heated air throughout the home’s duct system.

There is no combustion chamber, gas burner, flue or combustion exhaust.

DOE has found that electric furnace heating elements already approach 100%
efficiency, meaning almost all of the electricity delivered to the elements
becomes heat. 3

However, 100% conversion efficiency does not mean 100% lower heating
bills. The cost of the electricity used to produce that heat is the
critical issue.

How a Gas Furnace Works

1. The thermostat calls for heat.
2. The furnace control system initiates the heating sequence.
3. Natural gas or propane enters the burner.
4. The fuel is ignited.
5. Combustion heats the heat exchanger.
6. The blower moves indoor air across the heat exchanger.
7. Warm air travels through the home’s supply ducts.
8. Combustion gases leave through the exhaust vent.

High-efficiency condensing gas furnaces extract additional heat from the
combustion gases, allowing water vapor in the exhaust to condense. This is one
reason modern condensing furnaces can achieve AFUE ratings above 90%.

How an Electric Furnace Works

1. The thermostat calls for heat.
2. The furnace activates one or more electrical heating elements.
3. Electrical resistance converts electricity into heat.
4. The blower moves air across the heating elements.
5. Warm air travels through the home’s ducts.
6. The heating elements switch off when the thermostat reaches the target temperature.

Because there is no combustion, an electric furnace does not need a combustion
flue or gas supply.

Gas Furnace vs Electric Furnace Efficiency

Efficiency is where this comparison becomes confusing.

An electric furnace can convert nearly all of the electricity it consumes into
heat at the heating element. DOE documentation describes electric resistance
furnaces as approaching 100% efficiency. 4

A gas furnace, on the other hand, loses some energy through combustion and
exhaust. A 95% AFUE furnace therefore converts approximately 95% of its fuel
energy into useful space heat under the standardized rating methodology.

So, on a simple equipment-efficiency basis, the electric furnace wins.
On operating cost, however, gas can still win.

Why a 100% Efficient Electric Furnace Can Cost More to Run

This is the most important concept in the gas-versus-electric-furnace
comparison.

Efficiency tells you how much of the purchased energy becomes heat. It does
not tell you how expensive that energy is.

Natural gas is commonly sold by the therm, while electricity is sold in
kilowatt-hours. One therm contains approximately 100,000 BTU of natural gas
energy.

An electric resistance furnace needs approximately 29.3 kWh of electricity to
produce the equivalent of 100,000 BTU of heat before considering small system
losses.

That means homeowners should compare the local price of approximately
29.3 kWh of electricity with the price of one therm of
natural gas, adjusted for furnace efficiency.

Example

Suppose:

• Electricity costs $0.16/kWh.
• Natural gas costs $1.20/therm.
• The gas furnace operates at 95% AFUE.

The electric furnace would consume roughly:

29.3 × $0.16 = $4.69

to produce approximately 100,000 BTU of heat.

The 95% AFUE gas furnace would need more than one therm of input to deliver
100,000 BTU of useful heat, resulting in a fuel cost of roughly:

$1.20 ÷ 0.95 ≈ $1.26

This simplified example shows why a nearly 100%-efficient electric furnace
can still be dramatically more expensive to operate than a gas furnace.

Important: Actual costs vary by utility rates, fixed charges,
furnace efficiency, electricity tariffs and heating demand. Use your local
utility prices for a meaningful comparison.

Gas Furnace vs Electric Furnace Operating Cost

Operating cost is usually the biggest reason homeowners choose gas over
electric resistance heating.

The calculation depends primarily on:

• Natural gas price
• Electricity price
• Furnace efficiency
• Annual heating demand
• Thermostat settings
• Home insulation
• Air leakage
• Duct losses

DOE’s residential furnace analysis illustrates how gas-furnace efficiency
changes annual fuel consumption. In one example, DOE compared 99%, 95% and
80% AFUE gas furnaces and found significant differences in annual energy use
and lifetime energy costs. 5

Gas Furnace vs Electric Furnace in Cold Climates

Both systems can provide reliable heat during very cold weather, but their
economics can differ considerably.

A gas furnace generates heat directly through combustion, so its heating
output does not depend on extracting heat from outdoor air.

An electric resistance furnace also generates heat directly. Its heating
capacity does not decline simply because the outdoor temperature becomes
extremely low, provided the home’s electrical system can supply the required
power.

This is different from an air-source heat pump, whose heating capacity and
efficiency generally decline as outdoor temperatures fall.

Therefore, between a gas furnace and an electric resistance furnace,
both can provide strong low-temperature heating.

The major difference in a cold climate is generally operating cost rather
than the ability to produce heat.

Gas Furnace vs Electric Furnace for Warm Climates

Electric furnaces become more practical when annual heating demand is low.

In a warm climate where the furnace operates for only a limited number of
hours each year, the higher electricity operating cost may have less impact
on the total annual bill.

This can make an electric furnace attractive when:

• Natural gas is unavailable.
• The home has relatively low heating demand.
• Electricity rates are favorable.
• The homeowner wants to avoid combustion equipment.
• Installation simplicity is important.

Gas Furnace vs Electric Furnace Installation Cost

Installation cost depends heavily on what infrastructure already exists.

Gas furnace installation

A gas furnace installation may require:

• Natural-gas or propane connection
• Gas piping
• Combustion venting
• Flue or exhaust modifications
• Condensate drainage for a condensing furnace
• Electrical connection
• Gas-safety controls

Electric furnace installation

An electric furnace does not require a gas line or combustion vent, but it can
require substantial electrical capacity.

A typical residential electric furnace may use a large electrical load when
all heating elements are energized.

The electrical service, breaker panel, wiring and disconnect must therefore
be sized correctly for the equipment.

Does an Electric Furnace Need a Bigger Electrical Panel?

It can.

This is one of the most important installation considerations.

Electric furnaces can draw substantially more electrical power than many other
household appliances. A contractor should calculate the required circuit,
breaker and service capacity before installation.

If the existing electrical service is already heavily loaded, an electric
furnace may require an electrical upgrade.

This additional cost should be included when comparing an electric furnace
against a gas furnace.

Gas Furnace vs Electric Furnace Comfort

Both furnaces can provide comfortable forced-air heating.

A gas furnace often produces relatively hot supply air during its heating
cycle.

An electric furnace also produces warm air, but the exact discharge temperature
depends on the number of heating elements energized, airflow and system
configuration.

A properly sized furnace with a good blower and correctly designed ductwork
can provide excellent comfort regardless of fuel type.

Comfort problems are often caused by incorrect sizing, poor airflow,
inadequate insulation or leaky ductwork rather than by the basic
heating technology.

Gas Furnace vs Electric Furnace Noise

Electric furnaces generally have a simpler sound profile because there is no
gas burner ignition or combustion process.

Most of the sound comes from the blower motor and airflow through the ducts.

Gas furnaces also have blower noise but may produce additional sounds during
ignition, burner operation and combustion.

A modern variable-speed blower can make either system relatively quiet,
particularly when operating at lower airflow levels.

Gas Furnace vs Electric Furnace Maintenance

Electric furnaces generally have fewer combustion-related components, which
can simplify maintenance.

However, they are not maintenance-free. Filters, blowers, electrical
connections, heating elements and controls still require attention.

Gas Furnace vs Electric Furnace Reliability

Both technologies can be highly reliable when properly installed.

Electric furnaces have an advantage in mechanical simplicity because they do
not have burners, gas valves, combustion chambers or exhaust systems.

Gas furnaces have additional components that must work correctly, including
ignition systems, flame sensors, gas valves and combustion controls.

However, a gas furnace from a reputable manufacturer that is properly sized
and maintained can provide many years of reliable service.

Gas Furnace vs Electric Furnace Safety

Gas furnace safety

Gas furnaces involve combustion, so installation and maintenance must be
performed correctly.

Potential hazards include:

• Carbon monoxide from improper combustion or venting
• Gas leaks
• Improper venting
• Heat exchanger problems
• Ignition or burner problems

Carbon monoxide alarms are strongly recommended in homes with combustion
appliances.

Electric furnace safety

Electric furnaces do not burn fuel and therefore do not create combustion
exhaust.

Their primary safety concerns are electrical:

• Improper wiring
• Overloaded circuits
• Loose electrical connections
• Failed heating elements
• Improperly sized breakers or conductors

Both types should be installed according to the manufacturer’s instructions
and applicable electrical, mechanical and building codes.

Gas Furnace vs Electric Furnace Lifespan

Actual lifespan depends on equipment quality, installation, maintenance,
operating hours and environmental conditions.

Electric furnaces can have relatively long service lives because their heating
elements and electrical controls are mechanically simpler than combustion
equipment.

Gas furnaces can also last for many years, although combustion components and
heat exchangers introduce additional potential wear points.

Instead of choosing solely based on expected lifespan, compare the expected
total cost of ownership.

Gas Furnace vs Electric Furnace and Carbon Monoxide

An electric furnace does not burn natural gas or propane and therefore does not
produce carbon monoxide as a byproduct of its heating process.

A gas furnace is a combustion appliance. Proper installation, combustion,
venting and maintenance are therefore important for safe operation.

This difference can be particularly important for homeowners who prefer to
eliminate combustion appliances from the home.

Keep in mind that an electric furnace does not make the entire house immune to
carbon monoxide. Other combustion appliances, attached garages and external
sources can still create CO hazards.

Gas Furnace vs Electric Furnace for Older Homes

Older homes require special consideration because electrical and gas
infrastructure may be outdated.

If replacing a gas furnace with an electric furnace

Check:

• Electrical service capacity
• Main electrical panel rating
• Available breaker space
• Existing wiring
• Duct condition
• Home insulation
• Air leakage

If replacing an electric furnace with a gas furnace

Check:

• Natural-gas availability
• Gas piping requirements
• Combustion-air requirements
• Venting options
• Local building codes
• Condensate drainage for a high-efficiency furnace

Improving insulation and sealing air leaks before replacing the furnace can
reduce the required heating capacity and energy consumption.

ENERGY STAR also recommends home sealing, insulation and duct sealing as ways
to improve heating and cooling performance. 6

Gas Furnace vs Electric Furnace for New Construction

New construction provides more flexibility because the HVAC system can be
designed alongside the home’s electrical, gas, duct and insulation systems.

If the property does not already have natural-gas service, installing a gas
furnace may require additional infrastructure.

An electric furnace avoids the need for gas piping and combustion venting, but
the electrical service must be capable of supporting the heating load.

For new construction, homeowners should also compare both furnace types with
an air-source heat pump before making a final decision.

Electric Furnace vs Heat Pump

This distinction is extremely important.

An electric furnace and an electric heat pump both use electricity, but they
are not equally efficient.

If your goal is to move from gas heating to electric heating, a heat pump is
usually worth evaluating before choosing an electric resistance furnace.

Gas Furnace vs Electric Furnace: Which Is Cheaper to Install?

There is no universal answer.

An electric furnace can have a simpler installation because it does not require
gas piping or combustion venting.

However, the installation may become more expensive if the home’s electrical
service requires an upgrade.

A gas furnace can be relatively inexpensive to replace when a home already has
correctly sized gas piping and an appropriate venting system.

A new gas installation can become significantly more expensive when gas
infrastructure does not already exist.

Gas Furnace vs Electric Furnace: Which Is Better for Apartments?

Electric heating can be particularly practical in apartments and smaller
properties where natural-gas infrastructure is unavailable or where the
building owner does not permit combustion appliances.

However, the operating cost should still be considered.

If electricity is expensive and the apartment has high heating demand, an
electric resistance furnace may produce substantially higher utility bills
than a gas system.

Where permitted and technically feasible, a heat pump may provide a more
efficient electric alternative.

Gas Furnace vs Electric Furnace for Basements

Both systems can heat basements effectively when properly sized and connected
to the duct system.

A gas furnace requires appropriate combustion air and venting. An electric
furnace avoids these requirements.

Basement installations should also consider drainage, humidity, return-air
pathways and access for maintenance.

Gas Furnace vs Electric Furnace During a Power Outage

Neither system normally works without electricity.

A gas furnace still requires electricity for its controls, ignition and blower.

An electric furnace obviously requires electricity for its heating elements
and blower.

Therefore, a gas furnace does not automatically provide heat during a power
outage simply because natural gas continues flowing.

A properly sized generator or backup electrical system can potentially operate
either furnace, subject to the equipment’s electrical requirements.

Gas Furnace vs Electric Furnace Environmental Impact

A gas furnace burns fossil fuel directly inside the home. This produces
combustion emissions that must be safely exhausted.

An electric furnace has no onsite combustion emissions.

However, the environmental impact of electric resistance heating depends partly
on the electricity generation mix supplying the home.

Electricity generated primarily from renewable or low-carbon sources can make
electric heating substantially different from electricity generated primarily
from fossil fuels.

A heat pump generally offers another major efficiency advantage because it
transfers heat instead of using resistance elements as the primary heat source.

Gas Furnace vs Electric Furnace: Which Is More Reliable?

Electric furnaces have a mechanical simplicity advantage because there is no
gas burner, ignition system, gas valve, combustion chamber or flue.

Gas furnaces have more components that can fail, including:

• Igniters
• Flame sensors
• Gas valves
• Burners
• Pressure switches
• Heat exchangers
• Vent systems

Electric furnaces can experience failures involving:

• Heating elements
• Relays
• Sequencers
• Limit switches
• Control boards
• Blower motors

Neither technology should be considered failure-proof. Correct installation
and maintenance have a major effect on reliability.

Gas Furnace vs Electric Furnace: Total Cost of Ownership

The lowest purchase price does not necessarily produce the lowest lifetime
cost.

Compare:

• Equipment price
• Installation cost
• Electrical upgrades
• Gas-line work
• Venting requirements
• Annual heating cost
• Maintenance cost
• Expected service life
• Repair costs
• Future utility rates

A more expensive high-efficiency furnace may be worthwhile if it substantially
reduces annual energy consumption.

Gas Furnace vs Electric Furnace: Decision Matrix

Gas Furnace Advantages

• Often lower operating cost where natural gas is inexpensive.
• Excellent performance in extremely cold weather.
• High heating output.
• Widely available technology in the United States.
• Works well with existing forced-air duct systems.
• Natural gas can provide substantial heat from relatively low fuel volume.
• High-efficiency models can achieve very high AFUE ratings.

Gas Furnace Disadvantages

• Requires combustion.
• Requires appropriate venting.
• Requires gas or propane infrastructure.
• More combustion components to maintain.
• Produces onsite combustion emissions.
• Potential carbon monoxide hazard if improperly installed or maintained.
• Fuel prices can vary significantly by location.

Electric Furnace Advantages

• Near-100% point-of-use heating efficiency.
• No combustion.
• No gas line required.
• No combustion exhaust or flue required.
• Simple heating mechanism.
• Can be installed in homes without natural-gas service.
• Generally straightforward maintenance.
• Can provide reliable heating in very cold outdoor conditions if adequate electricity is available.

Electric Furnace Disadvantages

• Electricity can be expensive compared with natural gas.
• High heating loads can produce large electricity bills.
• May require substantial electrical service capacity.
• May require panel or wiring upgrades.
• Does not provide cooling without a separate AC system.
• Usually less economical than a heat pump for substantial heating demand.

Gas Furnace vs Electric Furnace: Which Is Better?

Choose a gas furnace if:

• Your home already has natural-gas service.
• Natural gas is inexpensive in your area.
• You live in a cold climate.
• Your home has high annual heating demand.
• Your electrical service has limited capacity.
• You want strong heating output during extreme cold.

Choose an electric furnace if:

• Your home does not have natural-gas service.
• Electricity is relatively inexpensive.
• You live in a warm climate with low heating demand.
• You want to avoid combustion equipment.
• Installing a gas line would be expensive.
• Your electrical service can support the furnace.

Consider a heat pump instead if:

• You want electric heating with lower energy consumption.
• You also need air conditioning.
• You want one system for heating and cooling.
• Your electricity rates are favorable.
• You have solar electricity.
• You want to reduce reliance on direct fossil-fuel combustion.

Gas Furnace vs Electric Furnace: The Biggest Buying Mistake

Do not choose an electric furnace simply because it has a “100% efficiency”
rating.

That rating describes the conversion of electricity into heat, not the cost
of purchasing the electricity.

Likewise, do not choose a gas furnace solely because natural gas has
historically been inexpensive. Local utility prices, installation costs and
future energy costs can change the calculation.

The correct comparison is:

Installed cost + lifetime energy cost + maintenance + expected repairs.

How to Compare Your Local Heating Costs

Gather the following information before choosing a furnace:

1. Your electricity price in dollars per kWh.
2. Your natural gas price in dollars per therm.
3. Your proposed gas furnace AFUE.
4. The proposed electric furnace electrical input in kW.
5. Your estimated annual heating load.
6. The cost of installation.
7. Any electrical-panel upgrade cost.
8. Any gas-line or venting cost.

Then compare the estimated annual energy cost rather than simply comparing
furnace efficiency percentages.

A local HVAC professional can estimate annual heating demand using the home’s
design conditions and a proper load calculation.

Why Furnace Sizing Matters

A correctly sized furnace can be more important than choosing between two
similar equipment models.

Oversizing can cause frequent cycling, temperature swings and unnecessary
mechanical stress.

Undersizing can result in inadequate heating during the coldest weather.

Ask your contractor to perform a proper Manual J heating-load
calculation rather than simply installing a furnace based on the
size of the old unit.

Your contractor should consider insulation, windows, air leakage, floor area,
ceiling height, climate and other characteristics of the home.

Gas Furnace vs Electric Furnace: Final Verdict

The better furnace depends primarily on fuel prices, climate, existing
infrastructure and heating demand.

Gas furnaces generally win on operating cost in areas where
natural gas is inexpensive and the home requires substantial heating. They
are particularly attractive in cold climates because they can provide strong
heat without depending on outdoor temperatures.

Electric furnaces win on simplicity and point-of-use efficiency.
They do not require combustion, gas piping or flue exhaust, and their heating
elements convert almost all of their electrical input into heat. DOE confirms
that electric resistance furnace heating elements already approach 100%
efficiency. 7

But homeowners should not confuse high efficiency with low operating cost.
Electricity can be considerably more expensive per unit of useful heat than
natural gas, particularly in cold climates with high heating demand.

For most homes making a new electric-heating decision, compare an
electric furnace with an air-source heat pump before buying. A heat
pump can provide heating and cooling while typically using much less
electricity for the same amount of delivered heat than resistance heating.

Best choice for many cold-climate homes with cheap natural gas:
high-efficiency gas furnace.

Best choice for homes without gas service: heat pump first;
electric resistance furnace where a heat pump is unsuitable or unnecessary.

Best choice for low heating demand: electric furnace can make
sense, particularly where electricity rates are favorable.

Best all-electric option for many U.S. homes: properly sized
heat pump rather than conventional electric resistance heating.

Frequently Asked Questions

Is a gas furnace cheaper than an electric furnace?

In many U.S. markets, yes. Natural gas often costs less per unit of useful
heat than electricity used by a resistance furnace. However, local utility
prices determine the actual result.

Is an electric furnace 100% efficient?

Electric resistance heating elements are close to 100% efficient at converting
electricity into heat. DOE describes electric furnace heating elements as
approaching 100% efficiency. 8

Why is an electric furnace expensive to run if it is 100% efficient?

Because efficiency and energy price are different things. An electric furnace
can convert almost all of its electricity into heat while electricity itself
may cost much more per delivered BTU than natural gas.

Which furnace is better for a cold climate?

A gas furnace is often economically attractive in cold climates, especially
where natural gas is inexpensive. An electric furnace can provide reliable
heat in cold weather, but its electricity consumption can become expensive.

Does an electric furnace need a gas line?

No. Electric furnaces do not require natural gas or propane.

Does an electric furnace need a chimney?

No combustion flue is required because an electric furnace does not produce
combustion exhaust.

Does a gas furnace work without electricity?

Modern gas furnaces normally require electricity for controls, ignition and
the blower. Therefore, a typical gas furnace will not operate normally during
a power outage without an appropriate backup power source.

Is an electric furnace safer than a gas furnace?

Electric furnaces avoid combustion-related risks such as gas leaks and
combustion-related carbon monoxide production. However, they still require
correct electrical installation and protection.

Which lasts longer, gas or electric furnaces?

Both can last for many years when properly installed and maintained. Electric
furnaces have fewer combustion components, while gas furnaces contain more
mechanical and combustion-related parts.

Can an electric furnace replace a gas furnace?

Yes, provided the home’s electrical service can support the required load and
the ductwork and furnace capacity are properly designed.

Should I choose an electric furnace or heat pump?

If you want electric heating, a heat pump should generally be evaluated first.
An electric furnace uses resistance heating, while a heat pump transfers heat,
potentially providing substantially more heat per unit of electricity.

Can I use an electric furnace with central air conditioning?

Yes. An electric furnace can be paired with a separate central air-conditioning
system using the same ductwork.

Can I use a gas furnace with central AC?

Yes. This is one of the most common forced-air HVAC configurations in U.S.
homes: a gas furnace provides heating and a separate outdoor AC system
provides cooling.

What is the biggest disadvantage of an electric furnace?

Operating cost is usually the biggest disadvantage. Resistance heating can
consume large amounts of electricity, particularly in homes with high winter
heating demand.

What is the biggest disadvantage of a gas furnace?

Gas furnaces require combustion equipment, fuel infrastructure and proper
venting. They also have more components that require maintenance than a basic
electric furnace.

Related Furnace Guides

• Best Gas Furnaces for Homes
• Best Two-Stage Gas Furnaces
• Best Variable-Speed Gas Furnaces
• Best Single-Stage Gas Furnaces
• Best Gas Furnaces for Cold Climates
• Best Gas Furnaces for Older Homes
• Gas Furnace vs Heat Pump
• Single-Stage vs Two-Stage Furnace
• Two-Stage vs Variable-Speed Furnace
• 80% vs 90%+ AFUE Furnace

Sources

• 
  U.S. Department of Energy — Purchasing Energy-Efficient Residential Furnaces
  
• 
  U.S. Department of Energy — Electric Furnace Efficiency Analysis
  
• 
  ENERGY STAR — Furnace Key Product Criteria
  
• 
  ENERGY STAR — Furnaces
  
• 
  ENERGY STAR — Efficiency Definitions