Furnace Replacement Cost: 2026 Pricing by Fuel and Efficiency

Frequently Asked Questions

How much does a new gas furnace cost installed?

For a standard 80% AFUE single-stage gas furnace: $3,000-$5,500 installed. For a 95-96% AFUE two-stage: $5,500-$8,500. For a 97-98% AFUE variable-speed modulating furnace with ECM blower: $8,500-$15,000. All figures assume a straightforward swap with existing ductwork and gas line.

How long does a gas furnace last?

15-20 years is typical for a well-maintained gas furnace. Oil furnaces last 20-30 years. Heat pumps 12-18 years. Replace before the old unit fails mid-winter — planned replacements avoid emergency installation premiums and let you shop contractors.

Should I upgrade to high-efficiency 95%+ AFUE?

In cold climates where heating dominates, yes — the 10-15% fuel savings can pay back the upgrade cost in 7-12 years. In mild climates, the payback is longer and a standard 80% AFUE furnace often makes more financial sense. High-efficiency units also require a sidewall PVC flue, which may add or reduce install cost depending on your house.

Is a heat pump cheaper than replacing a furnace?

Depends on climate. In moderate climates (zones 3-4), cold-climate heat pumps often beat gas furnaces on total cost of ownership, especially with federal tax credits and utility rebates. In very cold climates, dual-fuel (heat pump + gas backup) is often the optimal system. Get quotes for both before committing to a direct gas swap.

What size furnace do I need?

A properly sized furnace handles your worst-case heating load at your design temperature, not your peak. Typical US homes need 30-60 BTU per square foot of heated space — a 2,000 sq ft home in a cold climate needs 80,000-100,000 BTU. A Manual J load calculation (included in any good quote) determines exact sizing. Oversized furnaces short-cycle and waste fuel.

Replacing a furnace is one of the most expensive mechanical projects in a home, and one of the most commonly overpriced. This guide breaks down 2026 costs for gas, electric, oil, and propane furnaces, explains what’s worth paying for (and what’s not), and shows how to compare HVAC quotes without getting squeezed.

Quick Answer on Furnace Replacement Cost

Installed in a typical 2,000 sq ft home in 2026:

Furnace Type / Efficiency	Installed Cost
Gas 80% AFUE single-stage	$3,000 - $5,500
Gas 90-95% AFUE single-stage	$4,500 - $7,000
Gas 95-96% AFUE two-stage	$5,500 - $8,500
Gas 97-98% AFUE variable-speed modulating	$8,500 - $15,000
Electric furnace	$2,500 - $6,000
Oil furnace	$5,000 - $10,000
Propane furnace	$4,000 - $9,000
Heat pump (cold-climate)	$7,500 - $16,000
Dual fuel (heat pump + gas)	$10,500 - $20,000

These assume straightforward swaps: existing ductwork stays, gas line is in place, flue adaptation is minor. Complex installs push costs 20-40% higher.

What Drives Furnace Cost Up

Fuel Type

• Natural gas: Cheapest fuel in most US regions. Most homes.
• Electric resistance: Cheapest to install, most expensive to operate. Rare outside of apartments and mild climates.
• Oil: Expensive fuel and shrinking contractor base. Most oil furnaces are replacements where switching fuel isn’t practical.
• Propane: Similar installed cost to natural gas. Fuel cost varies by region.

Efficiency (AFUE Rating)

AFUE (Annual Fuel Utilization Efficiency) tells you what percentage of the fuel becomes usable heat:

• 80% AFUE: Mid-efficiency. 80 cents of every fuel dollar becomes heat. Vents through the existing masonry chimney.
• 90-96% AFUE: High-efficiency. Requires sidewall PVC flue. Uses a secondary heat exchanger to extract more heat from exhaust.
• 97-98% AFUE: Condensing modulating. Top-tier. Varies output in small increments for consistent comfort.

Going from 80% to 95% AFUE saves 15% on heating bills. In cold climates with high gas prices, payback is 7-12 years. In mild climates, payback can stretch past 20 years.

Staging and Modulation

• Single-stage: Full-blast or off. Cheapest. OK for mild climates and smaller homes.
• Two-stage: Low-fire (~65% output) and high-fire. Better comfort, less on/off cycling.
• Modulating: Adjusts in 1% increments from 35-100% output. Best comfort. Pairs with variable-speed ECM blower.

Blower Type

• PSC (Permanent Split Capacitor): Fixed speed. Inefficient. Being phased out.
• ECM (Electronically Commutated Motor): Variable speed. Uses 25-50% less electricity. Quieter. Better for high-end systems.
• Variable-speed ECM: Ramp-up/ramp-down for quieter operation and better comfort.

Sizing and Load Calculation

Oversizing is the most common mistake in US HVAC installs. An oversized furnace short-cycles — turns on, heats fast, shuts off — which:

• Wastes fuel during startup and shutdown cycles
• Leaves temperature swings in the house
• Stresses components and shortens life

A proper Manual J load calculation is the first deliverable from any competent contractor. It considers square footage, insulation, windows, air leakage, and climate. Any contractor who sizes a furnace by “rule of thumb” or “same size as the old one” should be disqualified — the old one is probably oversized too.

Typical residential sizes:

• 1,500 sq ft in mild climate: 40,000-60,000 BTU
• 2,000 sq ft in cold climate: 80,000-100,000 BTU
• 3,000 sq ft in cold climate: 100,000-120,000 BTU

Ductwork Issues

Existing ducts are often:

• Too leaky (20-40% air leakage is typical in older homes)
• Undersized for modern high-efficiency airflow
• Poorly balanced between rooms

Sealing ducts with mastic or aeroseal costs $400-$1,500 and often delivers bigger savings than the furnace upgrade itself. Undersized returns cause airflow problems that reduce efficiency and shorten equipment life — fixing them adds $500-$2,500.

Venting

80% AFUE furnaces vent through the chimney. Upgrading to 95%+ AFUE requires a PVC sidewall flue out the side of the house. If your chimney is shared with a water heater, you may need to reline it ($400-$1,500) so the water heater vents safely after the furnace is removed.

Gas Line Upgrades

If the old furnace was 80,000 BTU and the new one is 100,000 BTU, the gas line may need upsizing. Expect $300-$900 for a short run, more for long runs through finished areas.

Thermostats and Controls

Modern furnaces support communicating thermostats (ecobee Premium, Honeywell T10 Pro) that optimize staging and comfort. A good smart thermostat is $200-$350 installed and included in most premium quotes.

Permits and Code

Most jurisdictions require a permit and inspection for furnace replacement. Permits are $75-$500 depending on locality. Skipping the permit is risky — insurance claims can be denied and home sales delayed when unpermitted work is discovered.

Gas vs. Heat Pump: The Big Decision

In 2026, many homeowners face a real choice between replacing a gas furnace with another gas furnace, or switching to a cold-climate heat pump. The tradeoffs:

Gas furnace pros:

• Lower install cost
• Simpler system
• Works in any climate
• No disruption to existing electrical service

Heat pump pros:

• Federal tax credit up to $2,000 (Energy Efficient Home Improvement Credit)
• Utility rebates often $500-$8,000
• Combined heating + cooling (replaces both furnace and AC)
• Lower operating cost in moderate climates
• Aligns with gas phase-out policies in some states (CA, NY, etc.)

Dual fuel: Heat pump for most heating, gas backup for the coldest nights. Common in climate zones 5-6 where heat pumps alone struggle below 20°F. Most expensive upfront but optimizes operating cost.

Before replacing a gas furnace with gas, get at least one heat pump quote for comparison. The economics have shifted dramatically with tax credits and rebates.

Getting Real Quotes

HVAC quotes vary wildly. Same house, same brand, $3,500 to $11,500. Here’s how to compare:

1. Require a Manual J load calculation. In writing. Any contractor who skips this is using guesswork.
2. Get exact model numbers. Furnace brand, series, AFUE, BTU, and blower type should be in the quote.
3. Itemize accessories. Thermostat, humidifier, media air cleaner, UV light — each should be a separate line.
4. Ductwork work. Sealing, modifications, new returns — itemize or decline.
5. Ask about the crew. In-house employees or subs? NATE-certified? How many units a year?
6. Warranty terms. Manufacturer warranty (typically 10 years parts, 1 year labor on compressor) and contractor labor warranty (1-10 years depending on quality).
7. Three quotes minimum. Include at least one local contractor and one regional chain.

Red Flags

• Sizing without a load calculation
• No written scope of work
• Quotes that don’t specify AFUE or model number
• Pressure to sign same-day for a discount
• Cash-only or large up-front deposits (over 30%)
• Refusal to pull permits
• “Lifetime” warranties with vague terms
• Brand-new companies with no track record

Brands and Tiers

Premium tier (15-25% price premium, best comfort, best warranty):

• Lennox (Signature series)
• Carrier (Infinity series)
• Trane (XC and XV series)
• Bryant (Evolution series — Carrier-owned)

Mid-tier (most common, best value):

• American Standard (Trane-owned)
• Heil, Day & Night, Tempstar (ICP / Carrier family)
• Ruud, Rheem

Value tier:

• Goodman
• Amana (Goodman-owned)
• Payne

Brand matters less than installer quality. A mid-tier Goodman installed by a great contractor will outperform a premium Lennox installed by a mediocre one. The #1 predictor of system reliability is installation quality, not the label on the cabinet.

How to Budget the Project

For a typical 2,000 sq ft home replacing a failing 80% gas furnace with a 95% AFUE two-stage, ECM blower model in 2026:

• Furnace (mid-tier brand) equipment: $2,400
• Installation labor: $1,800
• New PVC flue (required for 95% AFUE): $450
• New thermostat (programmable): $250
• Permit: $150
• Existing ductwork sealing: $400 (optional but worth it)
• Contingency for surprises: $300
• Total: $5,750

For a 97% AFUE modulating variable-speed premium setup in the same home: $9,000-$13,000.

For a cold-climate heat pump replacing both furnace and AC: $12,000-$18,000 before tax credits and rebates.

Timing

• Late spring and early fall are the cheapest times to replace a furnace — contractors are slow.
• Winter emergency replacements carry a 15-30% premium.
• Schedule the tune-up in the spring or fall of the 10th year of ownership so you have a complete picture of remaining life before the next winter.

Related Reading

• Central Air Conditioning Installation Cost
• Heat Pump Installation Cost — electrify and replace both AC + furnace in one system
• AC Tune-Up Cost
• Best Smart Thermostats
• HVAC Maintenance Checklist
• How to Change a Furnace Filter
• Water Heater Replacement Cost
• How to Install Attic Insulation
• Winterize Your Home Checklist