In the Colorado Springs market, a standard-efficiency gas furnace replacement typically runs $3,500 to $6,000 installed, and a high-efficiency condensing furnace typically runs $6,000 to $10,000 installed. Premium modulating systems with variable-speed blowers run higher still.
Those are typical market ranges for our area, not a quote. Three things move a furnace quote more than anything else: the efficiency tier you pick, whether the new unit can use your existing venting, and whether your ductwork can handle the airflow the new system wants.
There is also a local factor that changes the size of the furnace you need. At 6,035 feet, the BTU number printed on the box is not the BTU number you get. More on that below, because getting it wrong is the most common expensive mistake we see on furnace replacements here.
Typical market ranges for our area:
| System | Typical Colorado Springs market range, installed |
|---|---|
| 80% AFUE single-stage gas furnace | $3,500–$6,000 |
| 80% AFUE two-stage gas furnace | $4,500–$7,000 |
| 95–97% AFUE condensing furnace | $6,000–$10,000 |
| Modulating, variable-speed premium tier | $8,000–$13,000 |
| Add: venting conversion for a condensing unit | $500–$1,500 |
| Add: chimney liner for an orphaned water heater | $500–$1,500 |
| Add: significant duct modification | $1,000–$3,500 |
The bottom three rows are the ones that surprise people, because they have nothing to do with the furnace itself. They come from what the new furnace requires of the house around it.
Gas furnaces are rated at sea level. The industry derating standard is roughly 4% for every 1,000 feet of elevation, which puts Colorado Springs at about 24% off the nameplate rating.
Two mistakes follow from ignoring this. The common one is matching the replacement to the old unit's nameplate without checking whether the old unit was ever correctly sized. The other is oversizing to compensate, which produces a furnace that short-cycles, heats unevenly, and wears out its ignition components early.
The fix is a Manual J load calculation that accounts for our design temperatures, which means planning for overnight lows around -10°F to -15°F rather than an average winter night. Square-footage rules of thumb do not survive contact with our altitude. We go deeper on this in our guide to high-altitude HVAC.
The equipment also has to be configured for elevation: correct orifice sizing, adjusted manifold gas pressure, and in many cases a manufacturer high-altitude kit. A furnace installed at sea-level default settings will over-fire or under-fire here, and incomplete combustion is a carbon monoxide concern, not just an efficiency one.
An 80% AFUE furnace vents combustion gases up a flue. A 90%+ condensing furnace extracts so much heat that the exhaust comes out cool and wet, so it vents through PVC out a sidewall and needs a condensate drain. Going from 80% to high-efficiency is not just a better furnace, it is a different venting system.
This one catches homeowners off guard. In a lot of older Colorado Springs homes, the furnace and the gas water heater share a single chimney flue. The furnace is the big appliance and it is what makes that flue draft properly. Pull the furnace off it and put in a condensing unit that vents out the wall, and the water heater is left alone in a flue far too large for it.
An orphaned water heater in an oversized flue can fail to draft, which means combustion gases spilling into the house. The correct fix is usually relining the chimney to a diameter the water heater can actually drive. It is legitimate work, but it should appear on the quote before the job starts, not as a change order after the old furnace is on the truck. Ask about it specifically if you are moving to high efficiency and your water heater shares the flue. If the water heater is also near end of life, replacing both at once is often the cheaper path, and our water heater installation labor is $999 with parts at cost.
Modern high-efficiency furnaces with variable-speed blowers want more airflow than a lot of older duct systems were built to deliver. Undersized returns are the usual culprit. You can install a great furnace on bad ductwork and get mediocre comfort, noise, and premature wear.
A single-stage furnace is either off or at full output. Two-stage runs lower most of the time, and modulating adjusts continuously. Each step up costs more and delivers steadier temperatures and quieter operation.
A furnace in an open basement is a straightforward swap. One in a tight attic, crawl space, or closet takes longer and sometimes requires modifications just to get the new unit in.
We size for altitude, check your venting and ductwork, and give you an itemized quote before any work begins.
Book an Estimate →The premium modulating furnace is a genuinely nice piece of equipment. It is also frequently oversold.
For most Colorado Springs homes, a properly sized two-stage furnace matched to ductwork that can actually move the air will outperform a top-tier unit sized by rule of thumb and installed on undersized returns. If your budget has a ceiling, spend it on getting the load calculation and the ductwork right before you spend it on features.
One place the upgrade does pay off here: moving from an old 80% AFUE atmospheric-vent furnace to a modern sealed-combustion unit. Sealed combustion pulls its air from outside through a dedicated intake, which sidesteps the thin indoor air problem, and the secondary heat exchanger recovers heat that altitude otherwise costs you.
Also worth doing: ask about current utility rebates before you sign anything. Programs and qualifying equipment lists change year to year, so we check what is actually active when we quote rather than promising a number that may have expired.
Every winter we get calls from people who have already been told they need a replacement, and a meaningful share of them do not.
The most common no-heat call we run between November and February is a dirty flame sensor. It is a small metal rod that confirms the burner lit, and when it gets coated with residue the furnace lights and shuts down a few seconds later, over and over. Cleaning it is a minor repair. In the Colorado Springs market, common furnace repairs like a flame sensor, an igniter, a capacitor, or a limit switch typically run a few hundred dollars.
Before assuming the worst, check:
Replacement is the right call when the heat exchanger is cracked, when the unit is past roughly 15 to 20 years and needs a major component, when repair costs are stacking up year over year, or when it was never sized correctly for this altitude in the first place. A cracked heat exchanger is not a judgment call, though. That is a carbon monoxide risk and the unit comes out.
If your flame is yellow or orange instead of blue, or you smell gas near the furnace, call immediately. That is a safety issue.
Furnace replacement requires a permit through the Pikes Peak Regional Building Department, including an inspection of the gas connection and venting. A bid that skips the permit is not saving you money, it is deferring a problem to whenever you sell the house.
For more on what we do, see our heating and cooling page, or our commercial HVAC page for light commercial systems.
We run the load calculation, check your venting and ductwork, and itemize everything before we start. 579 Google reviews at 4.9 stars.
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