This is the question we get asked more than any other, and it's the one where homeowners are most likely to get a self-serving answer. So here's how we think about it, laid out plainly enough that you could apply it without us.
Start with age. Air conditioners in San Antonio see far more annual run hours than the national average, and a system that might last 20 years in a mild climate often reaches the end of its useful life here around 12 to 15. Under 10 years, lean toward repair. Over 15, lean toward replacement. Between 10 and 15 is where the rest of these factors decide it.
Then consider the cost of the repair against the cost of replacement. A common rule of thumb: if the repair costs more than about a third of a new system, replacement usually wins on total cost over the next several years. A $250 capacitor on a 12-year-old unit is easy — do the repair. A $2,400 compressor on that same unit is a much harder case, because you'd be putting a major new component into a system whose other parts are the same age.
Refrigerant type matters more than most people realize. Systems built with R-22 are the clearest case for replacement. That refrigerant is no longer produced, so any leak repair means paying a steep price for reclaimed supply, and you'll face the same problem again the next time. If your system is on R-22 and needs refrigerant work, replacement is almost always the better financial decision.
Count the repairs, not just the current one. Two or more service calls in the last two years is a pattern, and patterns on aging equipment continue. Each individual repair may look reasonable in isolation while the sum of them quietly exceeds what a new, efficient, warrantied system would have cost.
Factor in what the system is costing you to run. A 15-year-old unit operating at 10 SEER against a modern high-efficiency system is a meaningful monthly difference in a climate where you run cooling eight months a year. That gap doesn't make replacement free, but it legitimately shortens the payback period, and it should be part of the math.
What should make you skeptical: any contractor who recommends replacement without showing you a diagnostic reading, who won't quote the repair as an option at all, or who pressures you to decide the same day. A real recommendation comes with numbers you can see.
BB&M AC and Heating gives you both options in writing with the actual costs, including second opinions on quotes you've received elsewhere. Call (210) 876-7140 — the service call is free.