Pricing Guide
Furnace Installation Cost
Denver furnace installation typically ranges between $5,629-$7,746 on average, including the installation of a standard efficiency gas furnace with equipment and labor.
Updated February 21, 2026•By Editorial Staff
Gas furnace installation in Denver runs $4,452-$10,094 depending on efficiency and features. High-efficiency models (95%+ AFUE) cost more upfront but reduce heating bills by 15-20%. No utility rebates are available for furnaces in 2026; rebates focus on heat pumps.
How much does a new furnace cost in Denver?
Denver furnace installation and replacement cost typically ranges between $5,629-$7,746 on average for a standard efficiency gas furnace with equipment and labor included.
Total cost depends on the furnace type (gas vs electric), efficiency rating (80% vs 95% AFUE), BTU capacity for your home's square footage, and installation complexity. High-efficiency models cost more upfront but cut heating bills by 15-20%.
Furnace Replacement Cost
Rough estimates for the cost of installing a new furnace:
- Standard, single-stage gas furnace: $5,936-$7,725 for equipment and installation.
- High-efficiency, two-stage gas furnace: $6,784-$10,094 for equipment and installation, plus $848-$1,854 for PVC flue if switching from standard efficiency.
- Electric furnace: $5,512-$10,094 for the unit and installation, plus $530-$1,854 for a 220V circuit if converting from gas.
These are estimates and may vary depending on your specific situation. Larger homes or more complex ductwork will increase the installation cost.
Furnace cost by size
- System Size
- 40K BTU Furnace & Installation
- Cost Range
- $5,088 to $7,725
- System Size
- 60K BTU Furnace & Installation
- Cost Range
- $5,512 to $8,034
- System Size
- 80K BTU Furnace & Installation
- Cost Range
- $6,148 to $9,064
- System Size
- 100K BTU Furnace & Installation
- Cost Range
- $6,572 to $9,270
- System Size
- 120K BTU Furnace & Installation
- Cost Range
- $6,890 to $11,021
What's Included in Furnace Installation Cost?
A furnace installation quote from a licensed Denver HVAC contractor typically includes four cost components:
What's in your installation quote
- Equipment (40-60%): The furnace unit. Standard 80% AFUE single-stage gas runs $2,200-$3,500. High-efficiency 95%+ AFUE two-stage models run $3,200-$5,500.
- Labor (25-35%): Removal of the old furnace, installation, gas line connections, electrical wiring, and thermostat setup. Typical labor runs $2,650-$6,180 depending on complexity.
- Materials and supplies (5-15%): PVC venting for high-efficiency units ($848-$1,854 if upgrading from standard efficiency), gas piping, electrical connections, sheet metal transitions, and mounting hardware.
- Permits and inspection: Denver metro building permits for furnace replacement run $75-$150. Required for gas line work and new installations.
Not included in most quotes: ductwork modification ($1,500-$5,000+), electrical panel upgrades ($3,392-$6,386 if needed for electric furnaces), or thermostat upgrades ($150-$500). Ask your contractor for a detailed line-item breakdown before signing.
What size furnace do I need?
Several factors determine the right furnace size for a home:
Furnace sizing factors
- Square footage: Larger spaces need more BTUs. A 1,000 sq ft home needs 40,000 BTUs; a 3,000+ sq ft home needs 120,000 BTUs.
- Climate: Denver's altitude and cold winters (below 0°F nights) mean sizing runs higher than national averages for comparable square footage.
- Insulation: A well-insulated home requires a smaller furnace. Older Denver homes with minimal insulation typically need the higher end of the BTU range.
- Number of windows: Large or older single-pane windows increase heat loss, pushing BTU requirements up.
- Number of floors: Multi-story homes require more BTU capacity to maintain consistent temperature across all levels.
Furnace capacity by home size
| Area Size | Blower Tonnage | Details |
|---|---|---|
| 1000 sq. ft. & below | 2 tons | |
| 1000 sq. ft. - 2000 sq. ft. | 3 - 4 tons | |
| 2000 sq. ft. - 3000 sq. ft. | 4 - 5 tons | |
| 3000 sq. ft. & above | 5 tons |
Why furnace sizing matters
An improperly sized furnace creates problems that compound over time:
Problems caused by wrong furnace size
- Inefficiency: An undersized furnace runs constantly without reaching setpoint, driving up energy bills. An oversized furnace short-cycles - turning on and off every few minutes - which is equally wasteful and hard on components.
- Comfort: Short-cycling leaves cold spots and temperature swings. The furnace never fully distributes heat before shutting off.
- Safety: An oversized furnace can shut off before completing a heating cycle, allowing unburnt fuel to accumulate - increasing carbon monoxide risk.
- Durability: Both undersized and oversized units face accelerated wear. Short-cycling and constant full-load operation shorten the system lifespan and increase repair frequency.
A proper Manual J load calculation accounts for your home's specific characteristics - square footage, insulation, window area, and orientation. Any contractor who quotes a furnace size without performing one is guessing.
Single-Stage vs Two-Stage vs Variable-Speed
Single-stage, two-stage, and variable-speed furnaces differ in how they modulate output - and that difference has real cost and comfort implications:
Single-stage furnace
→Full output or off
Runs at 100% capacity whenever it fires. Lowest upfront cost. Fine for smaller homes or mild climates, but tends to short-cycle in Denver's variable winters.
Two-stage furnace
→Low heat or high heat
Runs at ~65% capacity on mild days, switches to 100% when temperatures drop hard. More efficient than single-stage and quieter during the long low-demand runs.
Variable-speed furnace
→Continuously modulated
Adjusts output in small increments from roughly 40% to 100%. Most efficient type, quietest operation, best humidity control. Also the most expensive.
Two-stage and variable-speed furnaces cost more upfront but can reduce heating bills meaningfully over a 15-20 year lifespan. Your existing ductwork also matters - undersized ducts can negate the efficiency gains of a variable-speed system.
Should I convert my gas furnace to electric?
As solar and electrification become more common, many homeowners ask about converting to electric. A heat pump will better serve most electrification projects - it heats and cools, qualifies for $10,000+ in rebates, and runs 2-3x more efficiently than an electric furnace. A straight electric furnace makes sense mainly when the home already has solar and cost is the primary concern.
Key cost factors for gas-to-electric conversion:
Gas-to-electric conversion considerations
- Electrical panel capacity: Most gas homes have a 100A or 150A panel. An electric furnace typically needs a 200A panel or at minimum a dedicated 240V circuit. Panel upgrades run $3,392-$6,386.
- New circuit installation: Even with adequate panel capacity, you may need a 220V circuit run to the furnace location - typically $636-$2,472 depending on distance and access.
- Capping gas lines: Existing gas lines need to be professionally capped or removed. Cost is modest - $53-$227 - but it must be permitted and inspected.
Gas-to-electric conversion costs
- Gas-to-Electric Conversion Costs
- Electrical Panel Upgrade (if required)
- Cost Range
- $3,392 to $6,386
- Gas-to-Electric Conversion Costs
- Adding Electrical Subpanel (if possible)
- Cost Range
- $1,800 to $3,000+
- Gas-to-Electric Conversion Costs
- 220v Circuit Installation
- Cost Range
- $636 to $2,472
- Gas-to-Electric Conversion Costs
- Capping Gas Lines
- Cost Range
- $53 to $227
What is furnace AFUE rating?
The annual fuel utilization efficiency (AFUE) rating measures how much of the fuel a furnace burns actually becomes heat in your home, expressed as a percentage. A 95% AFUE furnace converts 95 cents of every dollar of gas into heat; the remaining 5 cents exits through the flue.
- High-efficiency gas furnaces: 90% AFUE or higher
- Standard-efficiency gas furnaces: 80% to 89% AFUE
As AFUE increases, so does installation cost. As of 2026, there are no utility rebates for gas furnace installations. Rebate programs now focus exclusively on heat pumps and electrification.
High efficiency vs standard efficiency: which is better?
Key differences between high-efficiency and standard-efficiency gas furnaces:
High-Efficiency (90%+ AFUE)
Best for most Denver homes
- 90-98% AFUE - less fuel wasted
- PVC venting runs horizontally through exterior wall - no chimney needed
- Lower monthly gas bills (15-20% savings vs standard)
- Fewer greenhouse gas emissions
- Higher upfront cost ($6,784-$10,094 installed)
- PVC flue adds $848-$1,854 when upgrading from standard
Standard Efficiency (80% AFUE)
Lower upfront, higher operating cost
- Lower installed cost ($5,936-$7,725)
- Uses existing metal flue and chimney - simpler retrofit
- Good option when replacing a standard-efficiency unit like-for-like
- 20% of every gas dollar exits through the flue
- Higher monthly heating bills over 15-20 year lifespan
When to Replace Your Furnace
Most gas furnaces last 15-20 years with regular maintenance. In Denver's climate, where furnaces run heavily from October through April, expect the lower end of that range. Signs it's time for a replacement:
Replacement warning signs
- Age over 15 years: Furnaces lose efficiency as components wear. A 20-year-old furnace operating at 70% effective efficiency costs significantly more per heating season than a new 95% AFUE unit.
- Repair costs exceeding $500 per visit: If you're spending $500+ on repairs more than once per season, the total often exceeds the cost difference of a new furnace within 2-3 years.
- Rising energy bills: A sudden 15-25% increase in winter gas bills with no rate change from Xcel Energy usually indicates declining furnace efficiency.
- Uneven heating between rooms: Hot and cold spots often signal a furnace that can no longer maintain consistent output, especially in Denver homes with multiple floors.
- Frequent cycling or unusual noises: Banging, popping, or squealing, or a furnace turning on and off every few minutes, typically indicates worn components.
If your furnace is under 10 years old, repair is usually the better option. Between 10-15 years, compare the repair cost to roughly one-third the price of a new furnace - if the repair exceeds that threshold, replacement makes more financial sense.
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Investment Options
Three tiers for every budget. All include installation, permits, and warranty.
Single-Stage Gas
Standard efficiency gas furnace.
Single-stage gas furnace
- Lower upfront cost
- Metal flue venting
- Standard installation
- 5-year parts warranty
Starting From
$5,936
Full range: $5,936-$7,725
Two-Stage High-Efficiency
High-efficiency gas furnace.
Two-stage high-efficiency gas furnace
- 15-20% lower heating bills
- PVC venting (quieter)
- No utility rebates for gas furnaces
- 10-year parts warranty
Starting From
$6,784
Full range: $6,784-$10,094
Electric Furnace
For electrification projects.
Electric furnace
- No gas required
- Works with solar
- Simpler maintenance
- 10-year parts warranty
Starting From
$5,512
Full range: $5,512-$10,094
Prices based on typical home in Denver metro. Actual costs depend on home size, ductwork condition, and equipment selection.
Consider Also
Other systems that may fit your needs and budget.
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AnsweringYour Questions
Frequently Asked Questions
Common questions about furnace installation costs in Denver.
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