Deciding whether to repair or replace an air conditioner comes down to weighing the repair cost against three things: the unit’s age, its energy efficiency compared to current models, and whether the specific fault is a cheap, common part or an expensive one like a compressor or a refrigerant leak.
Typical repair cost by fault
| Common fault | Relative cost | Notes |
|---|---|---|
| Dirty filter or coils | Free–low (DIY) | Resolves a large share of “weak cooling” complaints |
| Capacitor replacement | Low | Common, inexpensive, well-documented fix |
| Contactor relay | Low–moderate | Straightforward electrical component |
| Fan motor (indoor or outdoor) | Moderate | A common wear part on older systems |
| Refrigerant leak repair + recharge | Moderate–high | Requires certified handling; cost scales with how hard the leak is to find |
| Compressor replacement | High | The single most expensive common AC repair — often 30-50% or more of a full system’s replacement cost |
The efficiency factor
Unlike some appliances, AC systems have seen substantial efficiency improvements over the past 10–15 years. An older unit repaired rather than replaced keeps running at its original (lower) efficiency, which shows up as a real ongoing cost in summer electricity bills — worth factoring in alongside the repair quote itself, not just comparing repair cost to replacement cost in isolation.
A practical decision rule
Central air systems typically last 15–20 years. Combine that with the classic guidance in our repair-or-replace article: if the repair costs less than roughly half a full system replacement and the unit is under half its expected lifespan, repair usually makes sense. A compressor failure or a hard-to-find refrigerant leak on a system already past 10-12 years old is the classic case where replacement wins, especially once the efficiency gap is factored in.
What you can rule out yourself first
Many “the AC has stopped working” situations trace back to a dirty filter, blocked outdoor unit, or a thermostat set incorrectly — all covered in our air conditioner troubleshooting guide. These cost nothing to check and rule out before assuming an expensive repair is needed.
