How Much Does HVAC Replacement Cost? (2026 Guide)
HVAC replacement costs between $2,500 and $15,000+ nationally, depending on what is being replaced, the size of your home and the efficiency rating of the new equipment. Replacing only a furnace runs $2,500 to $6,000. Replacing a central AC unit alone runs $3,500 to $7,500. A full system replacement, both heating and cooling, runs $7,000 to $15,000, according to HomeAdvisor 2025 national data.
In Colorado and the Denver metro, high-altitude homes need properly sized equipment. Undersized units run longer cycles, wear out faster and drive up utility bills. Labor costs in Colorado run 10 to 15 percent above the national average due to high construction demand across the Front Range.
HVAC replacement cost by system.
Based on HomeAdvisor 2025 national data.
* National average estimates. Colorado jobs typically run 10 to 15 percent higher. Prices confirmed before any work begins.
What drives HVAC replacement cost.
System size and tonnage
HVAC equipment is sized in tons of cooling capacity. Most homes need 1.5 to 5 tons. A 3-ton system costs significantly more than a 2-ton unit for the same brand. Oversizing is as costly as undersizing: a too-large system short-cycles, wastes energy and wears out faster.
SEER rating and efficiency
SEER (Seasonal Energy Efficiency Ratio) measures cooling efficiency. The federal minimum is SEER 14 in Colorado. High-efficiency units at SEER 18 to 22 cost $1,000 to $2,500 more upfront but cut cooling bills by 20 to 35 percent annually. Xcel Energy rebates can offset part of that premium.
Ductwork condition
If your existing ductwork is leaking, undersized or in poor shape, a new system will not perform well. Duct sealing or partial duct replacement adds $500 to $3,000 to the project. A good HVAC contractor will inspect and pressure-test the duct system before recommending new equipment.
Brand and refrigerant type
Mid-tier brands like Carrier, Trane and Lennox generally cost 10 to 20 percent more than value brands but carry better long-term reliability data. Systems using older R-22 refrigerant (phased out in 2020) cannot be refilled and must be replaced entirely rather than repaired.
HVAC at altitude: what Denver homeowners need to know.
Denver sits at 5,280 feet and Colorado Springs at 6,035 feet. At high altitude, air is thinner and less dense, which affects how both furnaces and AC systems perform. A furnace rated for sea level will run at reduced efficiency in Denver without proper altitude adjustment.
Equipment must be derated for altitude. Most furnaces are derated 4 percent for each 1,000 feet above sea level. A reputable HVAC contractor will size the equipment accounting for your actual elevation, not just your square footage. Skipping this step leads to an undersized system that runs constantly in cold months.
Heat pumps are increasingly popular in Colorado because they cover both heating and cooling. Modern cold-climate heat pumps perform well down to 0 degrees F, which works for most of Colorado. Denver and Colorado Springs homeowners replacing older gas furnaces should ask for a heat pump comparison quote alongside a traditional furnace-and-AC quote.
Signs you need replacement, not repair.
Your system is over 15 years old. The average furnace lasts 15 to 20 years. Central AC units last 12 to 15 years. Repairing a unit in its final years is often a short-term fix that delays an inevitable replacement, sometimes by only one season.
Your system uses R-22 refrigerant. R-22 was phased out in 2020 and is no longer manufactured. Recycled R-22 is expensive and increasingly scarce. A system that still runs R-22 should be replaced rather than refilled when it next needs a refrigerant charge.
You are having frequent breakdowns. One repair a year is normal for an aging system. Two or more in a single season, especially in summer or deep winter, usually signals that the system is failing broadly rather than at a single point.
Your energy bills are rising without explanation. A degrading system works harder to hit the same temperatures. If your utility bills have climbed 15 to 25 percent over two years without a rate increase, declining system efficiency is a likely contributor.
How to get the best HVAC price.
Get at least three quotes from local HVAC contractors. Prices for the same equipment vary by 15 to 30 percent between contractors. Ask each one to include the Manual J load calculation (the industry-standard sizing method) so you can verify you are getting the right size unit.
Ask about Xcel Energy rebates. Xcel is the main utility provider across the Denver metro and Front Range, and it offers rebates on high-efficiency equipment. Rebates of $100 to $500 are available for qualifying furnaces and central AC units. Your contractor should be able to submit the rebate paperwork on your behalf.
Replacing both the furnace and AC at the same time costs more upfront but saves on labor, since the crew is already working on the same mechanical system. Replacing them one at a time means two mobilizations, two permits and two sets of labor charges.
HVAC replacement cost FAQ.
How long does HVAC replacement take?
A standard furnace or AC replacement takes 4 to 8 hours for a single unit. A full system replacement (both heating and cooling) typically takes one full day. If ductwork repairs are needed, add another half day to a full day. Most homeowners have heat or AC back the same day the crew arrives.
Do I need a permit for HVAC replacement in Denver?
Yes. Denver requires a mechanical permit for HVAC equipment replacement. Your contractor should pull the permit and schedule the inspection. A system installed without a permit can create issues when you sell the home. Permit costs in Denver typically run $75 to $200 for a residential HVAC replacement.
Is a heat pump worth it in Colorado?
For most Colorado homes, yes. Modern cold-climate heat pumps handle Denver winters down to around 0 degrees F before needing supplemental heat. They provide both heating and cooling from one system. Upfront cost is higher than a traditional furnace-and-AC combination, but lower operating costs and Xcel Energy rebates can close the gap over 5 to 7 years.
What size HVAC system do I need?
System size depends on your home's square footage, insulation quality, window area, ceiling height and altitude. A Manual J calculation is the correct way to size HVAC equipment. Contractors who size by square footage alone risk putting in an oversized unit that short-cycles and creates humidity problems. Ask to see the Manual J before approving the equipment choice.
Ready to get quotes from local HVAC pros?
Describe your project and get connected with an independent local pro. No obligation, no bidding wars.