2026 Denver-metro HVAC replacement cost guide

Installed replacement costs at a glance

Three jobs cover nearly everything homeowners call about. These are installed prices — equipment, labor, permit, and haul-away of the old unit — based on 2026 Denver-metro installed quotes. The low end is a clean swap with standard-efficiency equipment; the high end is high-efficiency equipment with ductwork or venting work included.

Full system replacement: $7,000–$15,000

Both pieces at once — furnace and AC as a matched set, installed the same visit. This is the most common full replacement because furnace and AC were usually installed the same week the house was built, so they age out together. The low end is a standard-efficiency matched pair on a straightforward swap. The top end is a 96%+ furnace paired with a two-stage or variable-speed AC, plus ductwork modifications or venting changes. Most Denver-metro homeowners land somewhere in the middle of the band. The big advantage of doing both: one install, one permit, one crew day, and warranties that start the same day.

Furnace only: $3,200–$7,800

An 80% AFUE single-stage swap sits at the low end. The top end is a 96–98% condensing furnace, two-stage or modulating, with a variable-speed ECM blower. The jump from 80% to 96%+ usually means new PVC venting and a condensate drain, which adds labor and materials. If your existing furnace is an older 80% unit vented through a metal flue or chimney, the high-efficiency path changes the venting entirely — make sure the quote accounts for it.

AC only: $3,500–$7,500

The low end is a standard-efficiency single-stage unit on a clean swap. The top end is 16+ SEER2 with a two-stage or variable-speed compressor, often with the indoor coil and line set replaced as well. One caution: replacing only the AC while keeping a much older furnace is sometimes penny-wise. The furnace's blower drives the whole system, and a 20-year-old blower on a brand-new condenser won't deliver the efficiency you paid for.

What drives the price up or down

Efficiency tier — the biggest lever

For furnaces, that's AFUE: 80% (standard, vents through a metal flue) versus 96–98% (condensing, vents through PVC, drains condensate). For AC, it's SEER2: entry-level units near today's federal minimum up to 16+ SEER2 at the premium end. Higher efficiency costs more up front and less every month. In Colorado's climate — long heating season, short intense cooling season — the furnace side of the efficiency equation usually matters more for your bills than the AC side.

Staging and blower technology

A single-stage unit is full-blast or off. Two-stage runs at low fire most of the time, ramping up only on the coldest or hottest days — quieter and more even. Modulating or variable-speed units fine-tune continuously and sit at the top of the price band. On the blower side, an ECM variable-speed motor moves air more efficiently and more quietly than an old fixed-speed PSC motor, and it meaningfully improves what a new AC can do even in cooling-only mode.

Home size and proper sizing

Denver-metro homes typically land between 60,000–100,000 BTU on the furnace and 1.5–5 tons on the AC. Bigger homes, two-story layouts, and big west-facing glass all push the load up. But the rule is: size from a Manual J load calculation, never from the old unit's label. Oversizing wastes money every month — and in our climate an oversized AC short-cycles instead of dehumidifying, which trades comfort for a higher bill.

Ductwork condition

This is the silent budget line. Leaky or undersized ducts can waste 20–30% of the heating and cooling you paid to produce, and modifying them typically adds $1,000–$3,000 to a job. Older homes with additions, finished basements, or conversions the original duct system was never designed for almost always need at least some duct attention. Pairing brand-new equipment with deteriorated ductwork is like putting racing tires on a car with a bent frame.

Electrical work

Many replacements are electrical non-events — the new equipment uses the existing circuit. But older 100-amp panels, AC additions where none existed, or long wire runs to a relocated condenser can require a panel upgrade or new dedicated circuits. When a panel upgrade is needed, budget roughly $1,500–$3,500 on top of the HVAC price. A quote that never mentions looking at your electrical panel hasn't finished evaluating the job.

Permits

Every city in the metro and Adams County require a mechanical permit and inspection for furnace and AC replacements. Permit fees generally run $150–$500 depending on the jurisdiction and scope — Brighton, Thornton, and Commerce City each set their own, and unincorporated areas like Henderson permit through Adams County. Legitimate quotes include the permit. If a quote doesn't mention it, either the installer is planning to skip it or it will appear as a surprise add-on.

Altitude — the Denver-metro factor

The metro sits around 5,000–6,000 feet, and gas equipment loses roughly 4% of its input per 1,000 feet of elevation. A furnace's nameplate BTU rating is measured at sea level; what it actually delivers here is meaningfully less. Proper installers account for this — adjusting orifices and manifold pressure per the manufacturer's altitude instructions — and size equipment for the altitude-adjusted load. An installer who has never mentioned altitude on a Denver-metro quote is a red flag.

Repair costs: what common fixes run in 2026

Not every breakdown means replacement. These are typical Denver-metro ranges for the repairs that make up most service calls:

Two things to know about that table. First, the diagnostic visit is worth paying: a proper diagnosis tells you whether you're buying a $250 fix or staring down a failing heat exchanger, and most reputable companies credit it toward the repair. Second, R-22 deserves special attention. If your AC still runs on R-22, it's at least a decade old, and a big recharge bill is often the moment replacement wins outright — you're pouring expensive, increasingly scarce refrigerant into equipment that's past its economic life.

Repair or replace? The expanded rule

The rule we stand behind: if the repair costs more than about a third of a new system and the equipment is past ~12 years, replacement usually wins on math alone.

There's a second heuristic worth knowing — the $5,000 rule. Multiply the equipment's age in years by the repair cost. Over $5,000, replacement usually wins. A 14-year-old furnace facing a $450 repair scores $6,300: replace. A 6-year-old AC facing a $400 repair scores $2,400: repair. It's rough, but it's directionally right more often than not.

Beyond the math, weigh a few more factors. Frequency: one repair is an event; two major repairs in two years is a pattern. Refrigerant: any R-22 system is on borrowed time. Warranty reset: a new system brings a fresh manufacturer parts warranty (typically 10 years when registered) plus new labor coverage — repairs on old equipment reset nothing. Efficiency jump: moving from an 80% furnace to 96%+ in a Colorado winter produces real, measurable gas-bill savings. And be honest about comfort problems: cold rooms and hot upstairs are usually airflow and duct issues, and new equipment bolted onto bad ducts reproduces them exactly.

What a legitimate quote includes

A real estimate is a document, not a number on a napkin. Before you sign, every quote should include:

• Exact equipment model numbers with AFUE and SEER2 ratings — "premium brand-name system" is not a specification.
• A documented sizing basis — a Manual J load calculation is the gold standard; at minimum, measured square footage, insulation, and windows, not "same size as the old one."
• The mechanical permit and inspection, in writing — pulled by the installer, scheduled, named in the quote.
• Every scope item spelled out — ductwork modifications, venting changes, electrical work, thermostat, condensate drain, line set, pad or stand for the condenser. "As needed" is not a scope.
• Haul-away and disposal of the old equipment, including refrigerant recovery.
• Warranty terms in writing — manufacturer parts (typically 10 years when the equipment is registered) plus the installer's labor warranty, with the labor term stated explicitly.
• A payment schedule tied to milestones — deposit, delivery, completion. Not full payment up front.

Red flags

• No mention of a permit. Either they're skipping it or it appears later as a surprise.
• A price quoted over the phone without seeing the home. Nobody can size, scope ductwork, or check venting and electrical from a phone call.
• Cash-only or "sign today" pressure. Legitimate contractors take normal payment methods and let you sleep on it.
• No model numbers. If you can't look up exactly what they're installing, you can't compare anything.
• Warranty promised verbally. If it isn't written into the contract, it doesn't exist.
• 30%+ under every other quote, unexplained. Something was left out — find out what before you find out after.

Timing: when you buy matters in Colorado

The best time to replace HVAC equipment is when you're not in an emergency. In Colorado, that means the shoulder seasons — roughly March–April and September–October. Crews are less slammed, scheduling is measured in days rather than weeks, and dealers sometimes run manufacturer or distributor promotions to fill the calendar.

The worst time is the first week of a January cold snap or a July heat wave. Everyone's equipment fails at once, backlogs stretch to weeks, equipment choices narrow to whatever is on the truck or in the warehouse, and emergency premiums apply — after-hours and weekend rates that never show up in a planned-install quote. A planned replacement also buys you the one thing an emergency never does: time to collect three real quotes and compare them properly.

If your system is past 15 years and limping, don't wait for it to die in the worst week of the year. Price the replacement in the shoulder season and schedule it on your terms.

Rebates and incentives — check before you buy

Free money exists, but it changes constantly, so treat this section as a starting point with an expiration date:

• Utility rebates: Xcel Energy runs heating and cooling rebate programs that change by program year — eligible equipment, amounts, and paperwork requirements all move. Check xcelenergy.com before you buy, not after. Some municipal and county programs exist too, and they appear and disappear without much announcement.
• Manufacturer promotions: equipment manufacturers run seasonal dealer promotions — usually spring and fall — that can meaningfully reduce the installed price. Ask every bidder what's running right now.
• What not to count on: the federal 25C energy-efficient home improvement credit ended December 31, 2025. Do not let anyone sell you on it for a 2026 install. If a salesperson's math depends on a federal credit, the math is fiction.

One rule covers all of this: get the rebate paperwork — exact model numbers and the AHRI certificate proving the rated efficiency — from your installer in writing before you sign. A legitimate installer produces it without blinking. If rebates are a selling point and the paperwork is "we'll handle it later," walk away.

Questions Denver homeowners actually ask

How this site works: Mile High HVAC Guide is an independent publisher. We don't install HVAC equipment. When you request help, we connect you with a licensed local contractor and may receive a referral fee from them. It never changes what you pay.

Replacement guides by city

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