Key takeaways
- Typical cost: $7,000–$12,000 for a combined AC and furnace replacement.
- Average AC repair: about $375
- AC + furnace replacement: $7,000–$12,000
- Typical lifespan: AC 12–15 yrs, furnace 15–20 yrs
- Timeline: Most AC or furnace swaps take one day.
- Permits: Replacing an AC, heat pump or furnace usually needs a mechanical permit, and the installer normally pulls it.
HVAC Replacement Cost at a glance
Replacing a central AC and furnace together typically costs $7,000–$12,000 installed. An AC alone runs about $2,500–$9,000 and a furnace $2,000–$6,900, depending on size, efficiency and brand. Most single repairs cost $250–$700.
| Job | Typical cost | Notes |
|---|---|---|
| AC + furnace replacement | $7,000–$12,000 | Average-size home, standard efficiency |
| Central AC replacement | $2,500–$9,000 | Higher-SEER2 units cost more up front |
| Furnace replacement | $2,000–$6,900 | 90%+ AFUE models run $3,300–$6,900 |
| Heat pump system | $5,000–$18,000+ | High-efficiency and multi-zone at the top end |
| Average AC repair | $250–$700 | National average about $375 |
| Capacitor replacement | $100–$400 | One of the most common summer repairs |
Prices run lowest in states like Arkansas, Mississippi and Alabama and highest in Hawaii, California and Alaska. See the full breakdown and cost by state →
HVAC cost questions
- What is the cost of AC + furnace replacement? The typical cost of AC + furnace replacement is $7,000–$12,000. Average-size home, standard efficiency.
- What is the cost of central AC replacement? The typical cost of central AC replacement is $2,500–$9,000. Higher-SEER2 units cost more up front.
- What is the cost of furnace replacement? The typical cost of furnace replacement is $2,000–$6,900. 90%+ AFUE models run $3,300–$6,900.
- What is the cost of heat pump system? The typical cost of heat pump system is $5,000–$18,000+. High-efficiency and multi-zone at the top end.
- What is the cost of average AC repair? The typical cost of average AC repair is $250–$700. National average about $375.
- What is the cost of capacitor replacement? The typical cost of capacitor replacement is $100–$400. One of the most common summer repairs.
- What is the cost of refrigerant leak repair? The typical cost of refrigerant leak repair is $200–$1,500. Recharge alone $100–$600 after the leak is fixed.
- What is the cost of compressor replacement? The typical cost of compressor replacement is $600–$3,000. Often triggers a replace-the-system decision.
- What is the cost of evaporator coil replacement? The typical cost of evaporator coil replacement is $400–$2,700. Coil leaks are common on older systems.
- What is the cost of blower motor replacement? The typical cost of blower motor replacement is $300–$2,000. Variable-speed motors cost more.
- What is the cost of thermostat replacement? The typical cost of thermostat replacement is $150–$500. Smart thermostats at the higher end.
Signs your HVAC system needs repair
- Warm air from vents or the system can't reach the thermostat setting
- Short cycling — turning on and off every few minutes
- Ice on the refrigerant lines or outdoor unit
- Grinding, squealing, banging or buzzing noises
- Water pooling around the indoor unit
- A sudden jump in energy bills
- Burning or musty smells from vents
One symptom doesn't always mean a big repair. A clogged filter or tripped breaker causes many no-cooling calls, so check those first.
Repair or replace: the quick rules
- Age: AC over 12–15 years or furnace over 15–20 years — lean toward replacing.
- The 50% rule: if a repair costs more than half the price of a new system, replace.
- The $5,000 rule: multiply the unit's age by the repair cost. Over 5,000? Replacement usually makes more sense.
- Old refrigerant: systems using R-22 are costly to recharge — replacement is usually the better value.
- Comfort problems: uneven rooms and high humidity often point to the wrong size system or poor ducts.
A compressor failure on a system older than 10 years is the most common tipping point toward full replacement.
What happens during an HVAC replacement
- A contractor does a load calculation to size the system for your home.
- You choose equipment by efficiency, features and budget.
- The old equipment is removed and refrigerant is recovered properly.
- New equipment, line set and drain are installed; ducts are sealed or modified as needed.
- The system is charged, tested and the thermostat set up. Most installs take one to two days.
Maintenance that prevents costly repairs
- Change 1-inch filters every 1–3 months; thicker media filters every 6–12 months.
- Book a tune-up yearly — AC in spring, furnace in fall (heat pumps twice a year).
- Keep 2 feet of clearance around the outdoor unit.
- Flush the condensate drain line with vinegar a few times a year.
- Install CO alarms if you have a gas furnace.
Common hvac questions
How much does a new AC unit cost for a 2,000 sq ft house?
Most 2,000 sq ft homes need a 3–4 ton system. A central AC replacement alone typically runs $2,500–$9,000 nationally, and replacing both the AC and furnace costs about $7,000–$12,000.
Is it worth repairing a 15-year-old AC?
Usually not. Use the $5,000 rule: multiply the unit's age by the repair cost. If the result is over $5,000, replacing is usually the better value. A $400 repair on a 15-year-old unit scores $6,000.
How long does an HVAC system last?
Furnaces typically last 15–20 years, and central air conditioners and heat pumps 10–15 years. Long cooling seasons and skipped maintenance shorten those lives.
What size AC do I need for my house?
A rough rule is one ton of cooling per 500–600 square feet, but insulation, windows, climate and ductwork change that. Ask for a Manual J load calculation instead of a square-footage guess.
Should I replace my AC and furnace at the same time?
Often yes when both are over 12–15 years old. A matched system runs more efficiently, and you pay for one installation visit and one permit instead of two.
Why is my AC running but not cooling?
The usual causes are a clogged filter, a frozen evaporator coil, a tripped outdoor unit, a failed capacitor or low refrigerant from a leak. Replace the filter and check the breaker first; if that doesn't fix it, call a technician.
How much does an AC tune-up cost?
A tune-up typically costs about $75–$200 per visit. Many companies offer maintenance plans that bundle a spring AC and fall furnace check.
Are there rebates for a new heat pump?
Federal energy tax credits changed in 2025, so check current IRS guidance. Utilities and some states still offer rebates for high-efficiency heat pumps, so ask installers which programs apply.
Timeline, permits and DIY
How long it takes
Most AC or furnace swaps take one day. A full system with new ductwork takes 2–5 days.
Permits
Replacing an AC, heat pump or furnace usually needs a mechanical permit, and the installer normally pulls it.
DIY or hire a pro?
Filters, clearing debris from the outdoor unit and flushing the condensate line are safe DIY jobs. Refrigerant, gas and electrical work need a licensed technician.
Questions to ask contractors
Ask every bidder the same questions so you can compare quotes apples to apples.
- Will you do a Manual J load calculation instead of sizing by square footage?
- What SEER2, HSPF2 or AFUE rating is quoted, and does it qualify for rebates or tax credits?
- Are the permit, haul-away and thermostat included?
- What is the labor warranty, separate from the parts warranty?
Maintenance that prevents costly repairs
- Replace filters every 1–3 months
- Book a tune-up before each cooling and heating season
- Keep 2 feet of clearance around the outdoor unit
Frequently asked questions
How long does an HVAC system last?
Central AC units usually last 12–15 years, heat pumps 10–15 years and gas furnaces 15–20 years. Coastal salt air, heavy use and skipped maintenance shorten those numbers.
What size AC do I need?
Size depends on a load calculation (Manual J) — insulation, windows, layout and climate — not just square footage. Rules of thumb often oversize systems, which causes humidity problems and short cycling.
What SEER2 rating should I buy?
Federal minimums are 13.4 SEER2 in northern states and 14.3 SEER2 in the South. Higher ratings pay off fastest in hot climates where the AC runs most of the year.
Is a heat pump better than a furnace?
Heat pumps heat and cool efficiently in mild and moderate climates, and cold-climate models work well below freezing. In very cold regions, a furnace or a dual-fuel heat pump setup is often cheaper to run.
Why is my AC running but not cooling?
Common causes are a dirty filter, a frozen coil, a failed capacitor, low refrigerant from a leak or a dirty outdoor coil. Turn the system off if you see ice and call a technician if a new filter doesn't fix it.
How often should I service my HVAC?
Once a year for AC or furnace systems, and twice a year for heat pumps since they run in both seasons. Many contractors offer maintenance plans that include priority service.
Do I need a permit to replace my HVAC system?
In most cities, yes. Replacing equipment usually requires a mechanical permit and inspection. Licensed contractors normally pull the permit for you.
Can I replace an AC without replacing the furnace?
Yes, but the indoor coil and blower must match the new outdoor unit for rated efficiency. If the furnace is over 15 years old, replacing both at once is usually better value.
In-depth hvac guides
HVAC by city
Sources: PickHVAC — Furnace & AC replacement cost · Fixr — AC repair cost (2026). Ranges are rounded estimates; see our editorial policy.