Gas vs Electric Furnace: Which Should You Choose in Edwardsville, IL?

Your furnace is getting older, and replacing it is becoming harder to put off. Maybe it keeps short-cycling, repair costs are climbing, or you are starting to compare new systems before the next cold stretch hits Edwardsville.

Then comes the bigger decision: should you choose a gas furnace or an electric one?

For many Edwardsville homeowners with existing natural gas service, a high-efficiency gas furnace can offer lower heating costs during a Metro East winter. An electric furnace may be a better fit when gas service is unavailable, installation simplicity matters, or local utility rates make the numbers more favorable. The right choice depends on more than the equipment price. 

In this guide, we will compare operating costs, installation requirements, efficiency, and long-term considerations to help you choose the right furnace for your home.

Key Takeaways

• An electric furnace converts nearly 100% of its energy into heat, but electricity in Illinois costs roughly five times more than natural gas per unit of heat, so a gas furnace usually wins on monthly bills.
• In our illustrative Edwardsville example, a 95% efficient gas furnace costs about $570 per heating season to run versus about $2,670 for an electric furnace delivering the same heat.
• Electric furnaces are typically cheaper and simpler to install, especially in homes with no gas line, but many older homes need an electrical service upgrade first.
• Gas furnaces require venting, combustion safety checks, and carbon monoxide alarms; Illinois law requires a CO alarm within 15 feet of every sleeping room in homes that burn fossil fuel.
• Starting December 18, 2028, new non-weatherized gas furnaces must meet a 95% AFUE federal minimum, which matters if you are replacing an older 80% unit.
• The federal 25C tax credit for furnaces ended on December 31, 2025, so 2026 savings now come mainly from Ameren Illinois program incentives and contractor financing.

How Gas and Electric Furnaces Make Heat

Both systems do the same basic job. They heat air and push it through your ductwork with a blower. The difference is where the heat comes from.

A gas furnace burns natural gas in a combustion chamber. A heat exchanger transfers that heat to the air moving through the system, and the exhaust gases leave the home through a flue or vent pipe.

An electric furnace has no flame. It runs electric current through resistance heating elements, similar to a large toaster. Air passes over the hot elements and moves into your ducts.

That single difference drives almost everything else in this comparison: operating cost, installation needs, safety requirements, and comfort.

Efficiency: Why the Higher Number Does Not Win the Bill

Furnace efficiency is measured by AFUE, or Annual Fuel Utilization Efficiency. It tells you what percentage of the energy you buy turns into usable heat inside your home.

On paper, electric furnaces look unbeatable. The U.S. Department of Energy notes in its guide to furnaces and boilers that all-electric furnaces rate between 95% and 100% AFUE because they lose no heat up a chimney. The same guide also points out the catch: higher electricity costs in most of the country make electric furnaces an uneconomic choice.

Gas furnaces range more widely. Older standard units sit around 80% AFUE, meaning 20 cents of every dollar escapes through the flue. Modern condensing furnaces reach 95% to 98% AFUE by capturing extra heat from exhaust gases before they leave the home.

So the electric furnace wins on efficiency by a few percentage points. That advantage disappears the moment you look at what each unit of energy actually costs in Illinois.

What It Costs to Heat an Edwardsville Home Each Way

This is the section that decides the question for most homeowners.

According to U.S. Energy Information Administration data, Illinois residential customers paid an average of $11.25 per thousand cubic feet of natural gas in 2025. For electricity, EIA figures compiled for May 2025 through April 2026 put the Illinois residential average at 18.24 cents per kWh, and April 2026 set a record high of 20.47 cents per kWh (source: EIA Electric Power Monthly).

When you convert both fuels into the same unit of heat and factor in efficiency, the gap is large.

Heating option	Cost per million Btu of delivered heat
Gas furnace, 95% AFUE	About $11.43
Gas furnace, 80% AFUE	About $13.57
Electric furnace, 100% AFUE (18.24¢/kWh)	About $53.46
Electric furnace, 100% AFUE (20.47¢/kWh)	About $59.99

Now apply that to a home. Say your Edwardsville house needs 50 million Btu of delivered heat over a winter, a reasonable illustration for a moderately sized, reasonably insulated home in this climate.

• A 95% AFUE gas furnace would cost about $572 to run.
• An older 80% AFUE gas furnace would cost about $679.
• An electric furnace would cost about $2,673, or roughly $3,000 at the April 2026 electric rate.

That’s about a $2,100 difference per heating season between a high-efficiency gas furnace and an electric one. Over a 15-year equipment life, the gap can exceed $30,000.

Your own numbers will vary. Ameren Illinois supply rates, delivery charges, your home’s size, insulation, and thermostat habits all shift the totals. The ratio, though, stays stubborn: per unit of heat, electricity in Illinois costs close to five times as much as natural gas.

Upfront Cost and Installation Requirements

Electric furnaces win this round, and sometimes by a lot.

An electric furnace is a simpler machine. It needs no gas line, no flue, no combustion air supply and no condensate drain. The equipment itself usually costs less, and installation is faster.

The common surprise is the electrical side. Electric furnaces draw a heavy load, and many older homes in Edwardsville, especially around the Leclaire and downtown neighborhoods, were never wired for it. You may need to upgrade a 100-amp panel to 200 amps before an electric furnace can run safely alongside your other appliances.

Gas furnaces carry more installation requirements:

• A natural gas supply line sized for the unit
• Proper venting, either through an existing chimney with a liner or through PVC pipe for condensing models
• A condensate drain for high-efficiency units
• Combustion air and clearance requirements under the mechanical code

If your home already has gas service and a working vent path, replacing a gas furnace with another gas furnace is usually straightforward. Switching from electric to gas in a home with no gas line is a bigger project, since it requires running new service from the utility.

To understand your home’s specific needs, our team’s furnace installation and replacement service in Edwardsville starts with a load calculation and an inspection of your gas, venting, and electrical setup before we recommend any equipment.

Comfort in a Metro East Winter

Edwardsville winters aren’t Chicago winters, but they aren’t mild either. Long-term weather records show average January lows near 19°F, and the area once recorded -27°F in January 1977. Illinois State Climatologist normals put Edwardsville’s average annual snowfall at about 12 inches.

Gas furnaces produce noticeably warmer supply air, often 120°F to 140°F at the register. Your home heats up faster, and the air coming out of the vents feels warm to the touch.

Electric furnaces deliver air that feels cooler by comparison. They heat steadily, but on a single-digit night they may run longer to keep up, and that longer runtime shows up directly on your electric bill.

Electric furnaces do have comfort advantages of their own. They run quietly, with no burner ignition sound, and they do not produce combustion byproducts inside the cabinet.

Safety, Maintenance and Lifespan

Every fuel-burning appliance carries a carbon monoxide risk if it is not installed or maintained correctly. A cracked heat exchanger, a blocked flue or poor venting can push CO into living spaces.

Illinois addresses this directly. The state’s Carbon Monoxide Alarm Detector Act requires every dwelling unit to have at least one working CO alarm within 15 feet of every room used for sleeping. Homes that do not burn fossil fuel for heat, ventilation or hot water and are not attached to a garage may be exempt.

That means a gas furnace adds a few ongoing responsibilities:

• Annual inspection of the burners, heat exchanger and flue
• Combustion and gas pressure checks
• Testing CO alarms and replacing them at the end of their rated life

Electric furnaces need less attention. There is no combustion to tune, so maintenance mostly covers filters, the blower motor, electrical connections and the heating elements. They still need regular filter changes and an occasional professional check.

On lifespan, the Department of Energy puts the typical life of a gas furnace at 15 to 20 years. Electric furnaces often last as long or longer because they have fewer stressed components, though heating elements and sequencers can fail and need replacement along the way.

Edwardsville Permits, Codes and Rules to Know

Local rules shape what your installation looks like, so it is worth knowing them before you choose.

The City of Edwardsville Public Works Department enforces the 2021 International Mechanical Code and 2021 International Residential Code, both adopted in January 2023, along with the 2020 National Electrical Code and the Illinois Energy Conservation Code. A licensed contractor installs your system to those standards.

A few local details matter for this decision:

• Electrical upgrades need a permit. The city requires permits for electrical upgrades, and its current fee schedule lists an electrical service upgrade or replacement at $20 for a one-family dwelling. That applies if an electric furnace requires a larger panel.
• Historic districts may add a step. Homes in the Leclaire, St. Louis Street and Downtown historic districts may need a Certificate of Appropriateness for exterior changes, which can include new sidewall vent terminations for a condensing gas furnace.
• Working without a permit is costly. The city’s fee schedule lists fines of up to $750 per day for construction without a required permit.

Permit requirements can change, so confirm current rules with Edwardsville Public Works at (618) 692-7535 before you begin work. If you live outside city limits in Glen Carbon, Maryville, or unincorporated Madison County, your local building department sets its own process.

The 2028 Federal Furnace Standard

There is one more rule that affects the gas option specifically.

The Department of Energy finalized a standard requiring new non-weatherized gas furnaces to meet a minimum of 95% AFUE. Compliance begins December 18, 2028, and federal court upheld the standard in late 2025. In practice, that ends production of the standard 80% AFUE furnaces many Edwardsville homes still have in their basements.

If your current gas furnace is an 80% unit and you replace it now, you can still choose either efficiency level. Choosing a 95% condensing model today means you get lower operating costs immediately and are already aligned with where the market is heading. It also means planning for PVC venting and a condensate drain, which your installer should account for in the quote.

Rebates and Tax Credits in 2026

Incentives changed significantly this year, and some older information online is now wrong.

The federal Energy Efficient Home Improvement Credit, known as 25C, previously offered up to $600 toward a qualifying gas furnace. Congress ended that credit for equipment installed after December 31, 2025. Homeowners who installed qualifying equipment in 2025 could still claim it on their 2025 return, but 2026 installations do not qualify.

Locally, the Ameren Illinois Energy Efficiency Program offers instant incentives on qualifying high-efficiency equipment, including gas furnaces and heat pumps, applied at purchase through participating distributors and contractors. Ameren Illinois also runs an income-qualified program that can cover efficiency upgrades for eligible households. Incentive amounts and eligible equipment change each program year, so ask your contractor to confirm what applies to your specific model before you sign.

When an Electric Furnace Is the Right Call

Despite the operating cost gap, an electric furnace is the better choice in some situations:

• Your home has no natural gas service. Running a new gas line from the street can be expensive, and in some rural parts of Madison County, gas service is not available at all.
• The home is small or very well insulated. A low heating load shrinks the dollar difference between fuels.
• You heat a space only occasionally. A finished garage, workshop or addition used a few times a month may not justify gas installation.
• You are pairing it with a heat pump. In many systems, electric heat strips in the air handler act as backup heat while a heat pump does most of the work.
• You want no combustion appliances in the home. Some homeowners prioritize this for personal reasons, and that is a valid choice.

If none of these describe your home and you already have gas service, a high-efficiency gas furnace is usually the stronger long-term investment.

Where a Heat Pump Fits Into the Decision

Many homeowners who start with the gas-versus-electric question end up considering a third option.

A heat pump moves heat rather than creating it, so it can deliver two to three units of heat for every unit of electricity it uses in mild weather. That changes the electric cost math considerably compared with a resistance furnace.

In the Metro East climate, a popular setup is a dual fuel system. A heat pump handles heating through fall and spring and on milder winter days, and a gas furnace takes over when temperatures drop into the teens. You get efficient electric heat most of the season and the warmth and lower cost of gas during the coldest stretches, plus central air conditioning from the same outdoor unit in summer.

If your existing air conditioner is also near the end of its life, our heat pump installation service in Edwardsville can help you compare a dual-fuel system with a straight furnace and AC replacement.

Choosing the Right Furnace for Your Edwardsville Home

The gas-versus-electric furnace decision comes down to three questions. Do you have natural gas service? How large is your heating load? And how much are you willing to pay each winter for the simpler installation of an electric system?

For most Edwardsville homes with gas already connected, a 95% AFUE gas furnace delivers the lowest operating cost, the warmest supply air, and a system aligned with the 2028 federal standard. For homes without gas, smaller spaces or heat pump systems, electric heat earns its place.

The right answer for your home depends on details no comparison chart can see: your ductwork, your electrical panel, your insulation, and how your family actually uses the house. B & W Heating & Cooling has served Edwardsville and the Metro East since 1949, and our technicians can run a proper load calculation, check your gas and electrical capacity and give you a clear, upfront estimate for each option. 

Call B & W Heating & Cooling at (618) 867-4445 to schedule an in-home evaluation before your next heating season.

FAQ

Is a gas or electric furnace cheaper to run in Illinois?

A gas furnace is usually much cheaper to run. Based on recent EIA price data, electricity in Illinois costs roughly five times more than natural gas per unit of heat delivered, even after accounting for the electric furnace’s higher efficiency.

Do I need a permit to replace my furnace in Edwardsville?

Furnace work must meet the codes enforced by Edwardsville Public Works, and the city requires permits for electrical upgrades such as a panel upgrade for an electric furnace. Confirm current permit requirements with Public Works at (618) 692-7535 or ask your licensed contractor to handle the process.

Can I switch from an electric furnace to a gas furnace?

Yes, if natural gas service is available at your property. The project typically includes a new gas line, a vent system and a condensate drain for high-efficiency models, so it costs more than a like-for-like replacement.

Is there still a federal tax credit for a new gas furnace in 2026?

No. The federal 25C Energy Efficient Home Improvement Credit ended for equipment installed after December 31, 2025. Ameren Illinois program incentives may still apply to qualifying equipment, so check current offers before you buy.

Do I need a carbon monoxide detector with a gas furnace in Illinois?

Yes. Illinois law requires at least one working carbon monoxide alarm within 15 feet of every sleeping room in homes that burn fossil fuel for heat, ventilation or hot water.