How long does a central air conditioner last?

By Dana Whitlock. Updated October 2026.

Climate decides a lot here. In the Department of Energy's central air conditioner and heat pump analysis, split-system air conditioners average about 24.1 years in the North and 24.9 years in the hot-dry region, but only about 18 years in the hot-humid South, where systems run longer seasons in salty, damp air. Trade and inspector charts are far more conservative. A 2007 builders' study puts central air at 10 to 15 years (15 in its appendix), and inspector charts list central air conditioners at 7 to 15 years with condensers at 8 to 20. For most homes, 15 to 20 years is a fair expectation, less near the coast or in the Gulf states. The outdoor unit (compressor, condenser coil and fan) and the indoor evaporator coil are usually what decide when a system is done.

What wears out

The compressor

The compressor is the pump in the outdoor unit that moves refrigerant through the system, and it is the most expensive single part to replace. Low refrigerant charge, poor airflow, dirty coils and electrical problems all stress it. So a dead compressor is often the last chapter of a story that started years earlier.

The indoor evaporator coil

The coil above the furnace or inside the air handler carries cold refrigerant and collects condensation. Copper coils can develop pinhole leaks from formicary corrosion, which ACHR News describes as acids from airborne household chemicals etching the copper until it leaks refrigerant. These leaks can be hard to find and often lead to coil replacement.

Condenser coil and fan

The outdoor coil sheds heat into the air. Dirt, grass clippings and bent fins reduce how well it does that, which raises pressures and makes the compressor work harder. The condenser fan motor wears with age and heat.

Electrical parts

Capacitors, contactors and relays in the outdoor unit are frequent, low-cost failures, especially after heat waves. Handling them involves stored high voltage. This is a job for a licensed HVAC technician.

Refrigerant leaks

A properly sealed system doesn't use up refrigerant. If it needs refrigerant added, there is a leak somewhere. DOE's maintenance guidance lists refrigerant charge and leak checks as technician tasks.

Signs it's near the end

• The system runs but blows warm or only slightly cool air.
• Ice on the refrigerant lines or indoor coil.
• The technician has added refrigerant more than once.
• Loud buzzing, clanking or grinding from the outdoor unit.
• The breaker for the condenser trips during hot weather.
• Rising summer electric bills and rooms that won't cool.
• The system uses R-22 refrigerant, or it is near 15 to 20 years old.

What helps it last

• Clean or replace the air filter every month or two during cooling season, as DOE recommends, more often with pets or dust.
• Keep at least 2 feet of open space around the outdoor unit and clear leaves, grass and debris, per DOE.
• Ask for the outdoor coil to be cleaned during the yearly service visit if it looks matted with dirt or cottonwood fluff.
• Make sure the condensate drain line is flowing so the indoor pan doesn't overflow.
• Book a yearly service visit for refrigerant charge, leak and airflow checks.
• Reset a tripped breaker once. If it trips again, leave it off and call a technician.

Repair or replace?

Most AC failures are either cheap or expensive, with little in between. Capacitors, contactors and fan motors are small repairs, sensible on nearly any system that still uses a current refrigerant. Compressors, coils and repeat refrigerant leaks are where you need a pencil. Work out cost per remaining year: divide the repair price by the years the system can likely keep running, then compare it with the replacement cost shown above divided by about 15 to 20 years of new service. The cheaper one per year wins. The 50 percent rule is a faster check. A repair above about half the price of a new system, on a unit past 10 to 12 years, usually points to replacement. Refrigerant changes the call too. R-22 systems rely on recovered refrigerant, and new systems now use lower-GWP refrigerants under EPA's 2025 rules, so major repairs on older equipment are harder to justify.

Common symptoms

• Why is my AC freezing up
• Why is my AC humming but not running
• Why is my AC leaking water inside
• Why is my AC running but not cooling
• Why does my AC keep turning on and off
• Why does my AC keep tripping the breaker