Tony’s Real-World Cost Breakdown — What Homeowners Should Expect
When Tony talks about HVAC costs, he doesn’t pull numbers out of thin air — he’s quoting from years of actual installs.
“I’ve been installing furnaces for over two decades, and here’s what I tell every homeowner: You’re not just buying a furnace — you’re buying comfort, safety, and the skill it takes to put it all together right.”
For 2025, one of the most popular heavy-duty models on the market is the Goodman 80% AFUE 120,000 BTU Two-Stage Natural Gas Furnace (Model GR9T801205DN). But what does it actually cost to install a 120,000 BTU furnace like this?
Let’s walk through the real costs, line by line — from equipment and labor to ductwork, permits, and pro tips on how to save.
🏠 You Don’t Just Pay for the Furnace — You Pay for the Fit
When Tony gets a call asking, “How much for a new furnace?”, his first question is always:
“What’s under your hood?”
That’s because the cost to install a furnace depends heavily on what you already have — your ductwork, venting, electrical setup, and even where the furnace sits in the house.
Average 2025 Cost Ranges
Here’s what homeowners can expect:
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Equipment (furnace only): $2,900–$3,800
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Full Installation (equipment + labor): $4,800–$7,500
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Permits and extras: $150–$800
A Goodman 120,000 BTU two-stage furnace like Tony’s sits right in the middle of that range — powerful enough for large homes, but still efficient and affordable.
“A fair price isn’t the cheapest quote — it’s the one that includes all the right work and no corners cut.”
🔩 What’s Actually Included in Furnace Installation
Tony says one of the biggest homeowner mistakes is comparing quotes that don’t include the same things.
Here’s what a complete installation covers:
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Removing the old furnace and disposing of it properly
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Installing the new Goodman furnace
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Connecting gas lines and electrical
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Upgrading venting and flue components
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Adjusting or replacing duct transitions
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Testing pressure, airflow, and ignition
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Pulling permits and scheduling inspection
If a quote skips half of that? You’re paying for trouble later.
“It’s like buying a car without the tires. Sure, it’s cheaper — until you try to drive it.”
💡 Equipment Cost: The Furnace Itself
The Goodman GR9T801205DN retails for roughly $2,800–$3,500 in 2025, depending on your supplier and warranty plan. That’s just for the unit — not installation.
Here’s how it stacks up against competitors:
| Brand | Model | AFUE | Stage Type | Approx. Price (2025) |
|---|---|---|---|---|
| Goodman GR9T801205DN | Two-Stage | 80% | Two-stage | $3,000 |
| Trane S8X2 | Two-Stage | 80% | Two-stage | $3,600 |
| Rheem R802TA | Two-Stage | 80% | Two-stage | $3,400 |
| Lennox ML180 | Single-Stage | 80% | Single | $3,200 |
Tony’s takeaway:
“Goodman doesn’t pad their prices with branding. You get honest parts, good airflow, and a warranty that rivals anyone’s.”
🔗 Reference: Consumer Reports – Gas Furnace Ratings
⚙️ Labor: The Big Variable
Labor can make or break your final total — it typically accounts for 40–50% of the project cost.
In 2025, professional HVAC labor runs:
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$80–$150/hour (regional average)
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6–10 hours for a 120,000 BTU furnace install
What Labor Covers
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Removing the old unit
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Modifying or reconnecting ducts
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Gas line and electrical wiring
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New vent or flue installation
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System startup and testing
“If your installer spends less than six hours, something was skipped — or they’re Superman.”
A clean, professional install isn’t just about connections — it’s about precision tuning. Tony always measures gas pressure, static pressure, and temperature rise before signing off.
🔗 Learn more: Furnace Installation Cost Guide
🪚 Ductwork Modifications
Ductwork is the silent cost that sneaks up on many homeowners.
If your ducts are in good shape, the installer might only reseal connections and add transition fittings. But if they’re undersized, leaking, or 30 years old, expect $300–$800 extra.
Tony’s Rule of Thumb
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Ducts over 20 years old? Add $500 for modifications.
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Uninsulated attic ducts? Add $300 for insulation wrap.
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No return in a major room? Add $200 for balancing.
“A great furnace hooked to bad ductwork is like a Ferrari on bald tires — it won’t perform how it should.”
🔗 See: Smarter House – Duct Efficiency Tips
🔥 Gas Line, Venting & Electrical Upgrades
Older homes often need updates here. Tony lists typical 2025 add-on costs:
| Upgrade Type | Estimated Cost | Why It Matters |
|---|---|---|
| Gas line extension or valve replacement | $200–$600 | Ensures safe fuel delivery |
| New B-vent or flue liner | $300–$700 | Required for 80% AFUE systems |
| Two-stage thermostat upgrade | $150–$300 | Enables low/high fire staging |
| Electrical disconnect box or surge protector | $100–$250 | Protects control board from power surges |
Tony explains:
“Gas and vent lines are like the arteries of your furnace — if they’re weak or clogged, you’ll have performance problems or worse.”
🔗 Resource: Energy.gov – Furnace Venting & Safety
🧾 Permits, Inspections, and Local Codes
Every municipality has its own permit rules. In most areas, you’ll pay $100–$350 for permits and inspections.
Permits cover:
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Safe gas pressure
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Correct vent sizing
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Electrical grounding
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Proper combustion air clearance
Tony’s warning:
“If an installer says you don’t need a permit, walk away. That means they don’t want anyone looking at their work.”
📈 Regional Price Differences
Your location affects both material and labor pricing. Here’s a breakdown Tony’s seen in 2025:
| Region | Installed Cost Range | Notes |
|---|---|---|
| Midwest | $4,800–$6,000 | High heating load, moderate labor cost |
| South | $4,000–$5,200 | Fewer heating hours, lower demand |
| Northeast | $5,500–$7,000 | Harsh winters, expensive labor |
| West Coast | $5,000–$6,500 | Strict code and permit fees |
“I’ve done the same job in Ohio for $5,000 and seen it quoted at $6,800 in Massachusetts. That’s labor and licensing, not furnace quality.”
🔗 Data: Fixr – HVAC Cost Report 2025
💬 Real Homeowner Examples
Case 1 – Ohio (Tony’s customer)
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3,000 sq. ft. home, existing gas and ducts
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Goodman GR9T801205DN installed with minor vent work
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Total cost: $5,200
Case 2 – Colorado
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2,800 sq. ft. home, duct resizing and new flue liner
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Total cost: $6,100
Case 3 – Tennessee
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2,200 sq. ft. ranch, no duct changes
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Total cost: $4,750
Tony:
“Your house is unique. Costs depend on what we find under the hood — no two installs are identical.”
🧰 Optional Add-Ons and Comfort Upgrades
Many homeowners choose upgrades during installation for efficiency or convenience.
| Add-On | Cost Range | Benefit |
|---|---|---|
| Smart thermostat | $250–$400 | Better control of two-stage heating |
| Whole-home humidifier | $350–$600 | Improves winter comfort |
| Media filter rack or air purifier | $200–$500 | Cleaner air & less maintenance |
| Surge protector | $100 | Protects circuit board |
| Annual service plan | $200/year | Keeps warranty active |
Tony’s advice:
“Skip the shiny extras unless they actually improve comfort or efficiency. But a good thermostat? That’s worth every penny.”
💸 Cost Comparison: Single vs. Two-Stage vs. Modulating
| Furnace Type | Installed Cost | Efficiency | Comfort | Best For |
|---|---|---|---|---|
| Single-Stage | $4,000–$5,000 | 78–80% | Basic | Small or mild-climate homes |
| Two-Stage (Goodman GR9T801205DN) | $4,800–$6,000 | 80% | High | Medium-to-large homes, variable climates |
| Modulating | $6,500–$8,500 | 95–98% | Very High | Cold regions, premium systems |
“A two-stage Goodman gives you 90% of the comfort of a modulating unit for about 70% of the price.”
🧠 How to Save on Furnace Installation in 2025
Tony’s five proven money-saving methods:
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Ask for itemized quotes.
“A single-line quote is a guessing game — you deserve the breakdown.”
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Schedule in the off-season.
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Spring and early fall are slow months — installers offer 10–15% discounts.
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Bundle HVAC systems.
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Add a new A/C at the same time — saves $400–$600 on combined labor.
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Use energy rebates.
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Check local utility or EnergyStar rebates ($200–$400 typical).
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Do basic prep yourself.
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Clearing the area and removing debris can save up to 1 hour of billed labor.
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🔗 Check Rebates: EnergyStar – Rebate Finder
🧾 Tony’s Cost Checklist
Before signing your furnace install contract, make sure these items are confirmed:
✅ Correct furnace model and efficiency (Goodman GR9T801205DN – 80% AFUE)
✅ Permit and inspection fees included
✅ Two-stage thermostat compatibility
✅ Airflow and gas pressure test results provided
✅ Written 1–2 year labor warranty
✅ Manufacturer registration completed within 60 days
“A professional job ends with documentation — not guesswork.”
🔍 Bonus: What You’re Paying For
When you see a quote for $5,000+, Tony wants you to remember what’s in that number:
| Cost Component | Typical Share | Example |
|---|---|---|
| Furnace (Goodman 120k BTU) | 45% | $3,000 |
| Labor & Testing | 35% | $2,000 |
| Venting & Gas Line Upgrades | 10% | $500 |
| Permits, Thermostat, Materials | 10% | $500 |
| Total Estimated Cost | 100% | $6,000 |
💬 Tony’s Takeaway: “Know What You’re Paying For — Not Just the Price”
“The best furnace install isn’t the cheapest — it’s the one that’s done right. When you invest in a Goodman GR9T801205DN, you’re buying proven reliability. But remember, even the best furnace can’t make up for bad installation. Choose a qualified tech, ask the right questions, and protect your comfort for the next 20 years.”
✅ Final Word
In 2025, installing a 120,000 BTU Goodman two-stage furnace typically costs between $4,800 and $6,000 — depending on where you live and how your home’s system is set up. But that investment pays dividends in comfort, reliability, and lower long-term maintenance.
“At the end of the day,” Tony says, “you’re buying peace of mind. And a Goodman gives you that without draining your wallet.”
In the next topic we will know more about: Maintaining Your Goodman Furnace for Peak Efficiency: Tony’s Seasonal Checklist
