Key takeaways
- Short answer: Central air conditioners typically last 12–15 years, heat pumps 10–15 years and gas furnaces 15–20 years.
- AC: 12–15 years
- Heat pump: 10–15 years
- Gas furnace: 15–20 years
- Typical hvac cost: $7,000–$12,000 for a combined AC and furnace replacement.
Lifespan by equipment type
| Equipment | Typical lifespan | What shortens it |
|---|---|---|
| Central AC | 12–15 years | Salt air, dirty coils, refrigerant leaks |
| Heat pump | 10–15 years | Year-round use, skipped maintenance |
| Gas furnace | 15–20 years | Dirty filters, cracked heat exchanger |
| Ductless mini-split | 15–20 years | Clogged filters, poor install |
| Thermostat | 10+ years | Outdated tech more than failure |
Signs your system is near the end
- Repairs are needed every season
- It uses R-22 refrigerant (systems built before about 2010)
- Energy bills keep rising with the same usage
- Rooms heat or cool unevenly
- The furnace flame is yellow instead of blue, or CO alarms trip
How to make your HVAC last longer
- Replace filters every 1–3 months
- Get a professional tune-up every year
- Keep the outdoor unit clear of plants and debris
- Seal leaky ducts so the system runs less
Related questions
Should I replace a 15-year-old AC that still works?
Not necessarily. If it cools well and repairs are rare, keep it, but start budgeting. Replace it before a major repair if it uses R-22 refrigerant.
Do heat pumps wear out faster than AC units?
Slightly, because they run in both heating and cooling seasons. Expect about 10–15 years versus 12–15 for a cooling-only AC.
Does a home warranty cover old HVAC systems?
Many home warranties cover HVAC regardless of age, but they often cap payouts and exclude improper maintenance. Read the limits before relying on one.
Other hvac questions homeowners ask
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.
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.
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.
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.
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.
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.
HVAC at a glance
Timeline
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 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.
What HVAC repair and replacement costs
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.