Gas vs Electric Furnace Guide: 10 FAQs Every Homeowner Should Know

The fork in the road: why this choice matters

If you’re staring at two paths, a gas furnace or electric furnace  you’re not alone. This decision can shape 15–30 years of comfort, bills, and maintenance. Think of us as the neighbor who installs this gear every week: we’ll walk you through the same checklist we use in real homes. We’ll cover fuel availability, upfront cost, monthly bills, efficiency, safety, climate fit, maintenance, and lifespan, then layer in two pro-level steps: proper sizing and installation realities. Along the way, we’ll point you to helpful resources like our Sizing Guide, product options (gas, electric, heat pumps), and quick ways to get a quote. By the end, you won’t just “pick a furnace” you’ll know why it fits your home, budget, and climate. No fluff, just workable steps you can trust.

Start where every pro starts: what fuel do you have?

First question on every job: What fuel is already available? If your home has a natural gas line, a gas furnace is simple to integrate. If not, adding gas service can cost $1,000+ before you even buy equipment. That’s why many all-electric homes stick with electric furnaces or consider heat pump systems. Electric installs tie into your electrical panel, but often need high-amperage circuits (60A+) and sometimes a panel upgrade.

Here’s how we think through it on site:

• Gas on tap? A gas furnace is an easy contender.

• No gas + tight panel? Electric still works, but check panel capacity first.

• Mild climate + no gas? Consider a heat pump system for efficient heating and cooling.

Upfront costs: what installation really runs

Budget matters, and installed costs are where surprises creep in. Typical ballparks we see:

• Electric furnaces: ~$2,000–$4,500 installed.

• Gas furnaces: ~$3,000–$8,000 installed.

Why the spread? Gas units need safe venting, gas piping, and code checks. Electric units skip venting and gas lines, but new circuits or panel upgrades can add real dollars. In new construction or major remodels, plan for added ductwork, permits, and electrical work (often $3,000+ extra when starting from scratch).

Pro tip (budget): Get an all-in number that includes equipment, venting/electrical, permits, thermostat, start-up, and haul-away. If you want a fast ballpark, send photos through our Quote by Photo tool. 

Monthly bills: what you’ll actually pay to heat

Over the long haul, operating cost usually matters more than the purchase price. In most regions, natural gas heat costs less per unit of heat than electric resistance heat. That’s why gas furnaces often deliver lower winter bills. Electric furnaces can work fine but in cold snaps, they run longer and use more kWh, which adds up.

A quick homeowner check:

1. Look at your utility rates: $/therm for gas and $/kWh for electricity.

2. Ask us to estimate annual usage based on Manual J sizing (coming up).

3. Compare 10-year totals, not just year one.

Considering mild climates? A heat pump can be a smart middle path very efficient in cool weather and paired with electric backup. Explore R-32 heat pumps if your winters are moderate.

Efficiency ratings in plain English (AFUE made easy)

You’ll see AFUE on spec sheets: Annual Fuel Utilization Efficiency. Electric furnaces are 100% AFUE because all electricity turns into heat at the point of use. Gas furnaces commonly list 80–98% AFUE. Here’s the catch: efficiency ≠ cost. Even at 100% AFUE, higher electric rates can make an electric furnace more expensive to operate than a high-efficiency gas unit in many areas.

So, use AFUE to compare models within the same fuel type. Then, compare your local rates to understand the cost. If your climate is moderate, also stack in heat pumps they move heat rather than make it, which can be even cheaper to run than gas in shoulder seasons.

Safety, CO, and peace of mind

Gas furnaces are safe when installed and maintained properly, but they involve combustion. That means carbon monoxide (CO) risks if something goes wrong—like a cracked heat exchanger or venting issue. We always install CO detectors and recommend annual professional checks for combustion, venting, and heat exchangers.

Electric furnaces don’t burn fuel, so they don’t produce CO. That’s one reason all-electric homes often choose them especially if they value low maintenance and fewer combustion parts to monitor.

Safety checklist we use:

• CO detectors on each floor near sleeping areas.

• Annual check on gas units (combustion, venting, exchanger).

• Proper clearances from combustibles.

• Tight electrical connections and correct breaker sizing for electric units.

If you want easy reference docs, our Help Center has practical safety FAQs.

Climate fit: cold winters vs. milder seasons

Colder climates: Gas furnaces shine. They heat fast and maintain comfortable temps even in harsh winters. In very cold regions, an electric furnace can keep up, but run time and power draw often spike leading to higher bills.

Moderate climates: Electric furnaces or heat pumps work well, especially if your heating season is brief. A dual-fuel setup (heat pump with gas backup) can be ideal where winters swing: the heat pump handles mild days; the gas furnace takes over when it’s freezing.

Maintenance you’ll actually do (and what to budget)

Gas furnaces need annual service: combustion tune-ups, heat-exchanger inspections, gas line/vent checks, and safeties. Filters often need more frequent changes due to combustion byproducts. Expect higher yearly maintenance costs than electric.

Electric furnaces are simpler: filter changes and occasional coil cleaning. Fewer moving parts usually means fewer breakdowns.

Homeowner schedule we like:

• Every 1–3 months: Replace or clean filters.

• Annually (gas): Professional safety/combustion inspection.

• Every 2–3 years (electric): Coil cleaning and electrical checks.

• Any time: If you smell gas, see scorch marks, or trip breakers, shut it down and call.

Need filters, thermostats, or line sets? Browse Accessories to keep your system healthy.

Lifespan: how long each system tends to last

Electric furnaces commonly run 20–30 years, thanks to their straightforward design. Gas furnaces typically see 15–20 years, as combustion and heat exchangers add wear. Of course, good maintenance and proper sizing stretch those numbers.

What shortens life?

• Oversizing (short cycling cooks parts).

• Poor filtration (dusty coils/heat exchangers).

• Neglected annual checks on gas units.

• Voltage issues on electric units (loose lugs, weak breakers).

If you plan to stay in your home long term, it can be worth paying more upfront for the right match and clean install. If you might move in a few years, we’ll help you weigh payback vs. resale expectations.

Sizing, ducts, and panel checks (the quiet keys to comfort)

Equipment choice is only half the story sizing and airflow are what make systems feel great. We use Manual J load calculations to size in BTUs, then check duct sizing, supply/return balance, and static pressure. A perfectly good furnace can feel terrible if ducts are undersized or leaky.

On electric installs, confirm panel capacity (often 60A+ needed) and breaker/bus limits. On gas installs, confirm vent routing, combustion air, and condensate for high-efficiency models.

Quick homeowner mini-audit:

• Rooms that are too hot/cold? Note them.

• Old, noisy ducts? Consider repair or resizing.

• Limited electrical capacity? Ask about panel upgrades.

• Going to the heat pump? Ensure proper line set routing and condensate management.

Want a second set of eyes? Our Design Center can help you specify a clean install.