The most expensive mistake homeowners make on HVAC work is not choosing the wrong brand — it’s accepting the first quote. Get at least two or three bids for the same scope before deciding, and watch for a cheap bid that quietly skips the permit, the load calculation, or the panel assessment.
Run the numbers
HVAC Load Calculator computes live in your browser — free, no sign-up.
This page is a reference index: what each type of HVAC job should cost, what drives the variation, and how to tell a fair bid from a padded one. Use the table below to jump to the job you’re pricing, then read the bid-vetting section before you sign anything.
Quick cost index
| Job | Typical installed cost | See the full breakdown |
|---|---|---|
| AC capacitor replacement | $130–$400 | AC capacitor cost |
| AC compressor replacement | $800–$2,300 | AC compressor cost |
| AC repair (by failure type) | $150–$2,300 | AC repair cost |
| AC unit replacement (system exists) | $3,500–$7,500 | AC unit replacement cost |
| Central AC installation (no existing system) | $8,500–$19,400 | Central air installation cost |
| Furnace blower motor replacement | $450–$2,000 | Blower motor cost |
| Full HVAC system replacement (AC + furnace) | $5,000–$15,500 | This page |
| AC tune-up / furnace tune-up | $75–$200 per visit | HVAC tune-up cost |
| Ductwork replacement | $1,400–$7,000 | Ductwork replacement cost |
📊 Deciding whether to repair or replace?
Compare your own quotes with BidSmart, a bid-comparison tool from our team. Upload the quotes you’ve received and see how they stack up line-by-line — scope, equipment tiers, and the items a low bid quietly leaves out — before you sign anything.
Full system replacement: what the numbers actually mean
Replacing a central AC and gas furnace together (the most common whole-system job) runs $5,000–$15,500 for a typical home with existing ductwork in good condition. That’s a wide range, and the variation is almost never about the brand.
What drives a quote toward the low end:
- Single-stage equipment (entry-level tier)
- Reusing an existing line set and electrical disconnect
- No ductwork modifications required
- Competitive labor market
What drives a quote toward the high end:
- Two-stage or variable-speed equipment
- Line-set replacement (required when the old set is undersized, corroded, or leaks)
- Electrical panel upgrade (a 3-ton system may need a 240V/30A circuit that isn’t there)
- Permit fees (typically $150–$500 depending on the municipality; never skip this)
- Tight access (attic or crawl-space installs take more labor hours)
Premium high-efficiency systems (variable-speed inverter compressors, communicating controls) can push the total to $9,500–$20,000+. The efficiency math only pencils out if you’re staying in the house long enough to recover the premium, usually 8–12 years.
If you’re replacing only the outdoor AC unit while keeping an existing furnace and air handler, expect $3,500–$7,500 installed for most residential systems. See AC unit replacement cost for the matched-equipment and refrigerant-transition details.
If you’re adding central air to a house that doesn’t have it (new line set, new electrical circuit, new air handler or coil, possibly new ductwork), the range jumps to $8,500–$19,400. The high end covers homes that need a complete duct system added. See central air installation cost for the scope breakdown.
The repair-vs-replace decision
One formula that holds up in practice: multiply the unit’s age (in years) by the repair cost. If the result exceeds $5,000, replacement bids are worth getting.
Examples:
- $250 capacitor on a 10-year-old unit: $2,500: repair it.
- $1,400 blower motor on a 14-year-old unit: $19,600: get replacement bids.
- $900 compressor on a 6-year-old unit: $5,400: borderline; depends on whether the refrigerant is R-410A or the older R-22 (now discontinued and expensive to recharge)
The formula is a threshold, not a verdict. A 10-year-old unit with a good maintenance record and a compressor problem is a different situation from the same unit with a bad compressor, corroded coils, and a refrigerant leak. When the repair is borderline, ask the tech for a written condition assessment before deciding.
For the component-by-component repair cost breakdown (capacitor, contactor, fan motor, refrigerant leak, control board), see AC repair cost.
Why quotes on the same job spread so much
Wide spreads between quotes for the same job are the norm in residential HVAC, not the exception, and the spread almost always lives in the scope — what’s included and what isn’t — rather than in equipment markup.
The most common scope mismatches between competing bids:
Permit included vs. not included. Some contractors price permits separately; others absorb them. A bid without a permit is also a bid to do unpermitted work, which creates liability when you sell the house.
Load calculation performed vs. “matched the old unit.” Replacing a 3-ton unit with another 3-ton unit is not always right. A proper Manual J load calculation takes 30 minutes and occasionally reveals the home was oversized originally. Oversized systems short-cycle, wear faster, and control humidity poorly.
Line-set reused vs. replaced. An old refrigerant line set may be undersized for a modern system or contaminated with old oil. The right call depends on its condition and the refrigerant type of the new system (R-32 and R-454B, the replacements for R-410A, have different pressure requirements). Reusing a bad line set is a warranty-voiding move on some manufacturer installations.
Labor warranty on the installation. A 10-year manufacturer parts warranty is standard on both Carrier and Trane with registration. What isn’t standard is the labor warranty the dealer puts on their own work. One year is common; two to five is better. A dealer who won’t back their installation with a written labor warranty is telling you something about their confidence in the job.
Before you accept any bid, read it against the full checklist at the HVAC quote checklist.
Component jobs: what each repair should cost
For the common repair jobs that don’t require full system replacement:
AC capacitor ($130–$400 installed): the most marked-up single repair in residential HVAC. The part costs $10–$50. Quotes of $500–$700 for a standard swap are common and inflated. Full breakdown and red flags.
AC compressor ($800–$2,300 installed): the most expensive component repair. The rule of thumb is that a compressor replacement costs roughly half what a new system costs, which is why the age-times-repair-cost formula becomes especially relevant here. Full breakdown and repair-vs-replace math.
Furnace blower motor ($450–$2,000 installed): the wide range comes from motor type. A PSC (single-speed) motor runs $300–$1,100 installed. An ECM (variable-speed, electronically commutated) motor runs $600–$1,500+, but must be programmed to the specific system, which adds labor and sometimes requires an OEM part rather than an aftermarket one. Full PSC vs. ECM breakdown.
Annual tune-up ($75–$200 per visit): the single highest-ROI HVAC spend, not because one tune-up changes your bill, but because the tech who maintains your system is also the one catching a failing capacitor before it takes the compressor with it. Annual plans that bundle two visits (spring + fall) typically run $150–$350. What a real tune-up includes vs. a sales visit.
Before you sign: five questions for any HVAC bid
These apply to every job on this page, whether a $200 repair or a $15,000 replacement. Good answers are specific. Pressure is a bad answer.
- “What is the scope in writing: model numbers, permit, line-set status, and electrical?” A verbal scope is not a scope.
- “Did you perform a Manual J load calculation, or did you size it off the old unit?” The right answer names the load number.
- “What labor warranty do you include in writing, on top of the manufacturer parts warranty?”
- “Is the permit included in this price, and who pulls it?” The contractor should pull it; it should be in the price.
- “If I approve this repair and the system has another failure within 12 months, what’s your policy?” Good contractors have an answer. They’ve thought about it.
For the full per-job-type checklist (organized by replacement, compressor job, ductwork, and tune-up), see the HVAC quote checklist.
What’s not in this index
A few cost categories that didn’t make this list, and why:
Duct cleaning ($300–$1,000): the EPA’s position is that duct cleaning is rarely necessary unless there’s visible mold, a pest infestation, or substantial debris. Most duct-cleaning proposals are driven by upsell incentives, not measured airflow deficits. One honest explainer on the topic is planned for this cluster.
Near-me and service-territory pricing: we don’t have location data, so we don’t publish geography-adjusted estimates. The ranges above are national averages. Austin and Phoenix run hot; the Midwest and Southeast generally run cheaper on labor.
Per-model equipment prices: model-level price tables go stale within months as distributors adjust. The tier framing above (basic / two-stage / variable-speed) is a better planning frame than chasing specific model quotes.
If something you’re pricing isn’t covered here, the HVAC quote checklist has the contractor-vetting layer that applies regardless of the job type.
Weighing any of these repairs against replacing the whole system? Start with our new-system decision guide, and if a heat pump is on the table, read the heat pump vs. AC comparison before collecting bids.
Refrigerant work has its own cost structure, and the per-pound figure is the part most often misread.
