Your tech just quoted a $1,400 compressor on a 12-year-old AC. Repair it, or replace the whole system? Here's the simple decision rule plus the local context that should adjust it for a KC home.
Your tech just quoted a $1,400 compressor on a 12-year-old AC. Repair it, or replace the whole system? Here's the simple decision rule plus the local context that should adjust it for a KC home.
Reviewed by
Andy Mitchell, PE
Owner & Licensed Professional Engineer
Multiply the age of the system (in years) by the cost of the repair (in dollars). If the result is over 5,000, replace. If it's under, repair.
Example: a 12-year-old AC, $1,400 compressor repair → 12 × 1,400 = 16,800. Replace.
Example: an 8-year-old AC, $480 capacitor + contactor repair → 8 × 480 = 3,840. Repair.
It's a useful first cut. The full decision adds three KC-specific factors below.
If your AC uses R-410A refrigerant and it's older than 8 years, the math leans toward replace. Why: R-410A is being phased down by federal rule starting in 2025; supply is tightening and refrigerant prices on R-410A repairs have already risen. The current-generation refrigerant (R-454B, in some new equipment) is what new installs use. Refrigerant generation isn't a hard rule, but it tilts the math.
An AC is half of a matched system; the indoor evaporator coil is the other half. Replacing only the outdoor unit on a system more than 10 years old usually creates a mismatched pair that runs below its rated efficiency and shortens the lifespan of the new outdoor unit. If you're replacing the outdoor unit, plan on the indoor coil too — and run the numbers on a full furnace replacement at the same time if the furnace is also 12+ years old. Bundling cuts labor on the second visit.
A 12–15 year old KC AC is probably running at 8–10 SEER2 equivalent in real-world conditions. A new 15-SEER2 install delivers 40–60% lower cooling cost per BTU. For a KC home running the AC May–September, that's a real monthly bill difference that helps the replace math on a borderline call.
Three honest scripts we use on the phone:
If you have a quote in hand and want to think out loud — we built a Repair vs Replace tool on our homepage that runs the math live. You can also send us the quote and we'll review it free — including verifying that the repair scope is the right scope.
Multiply the age of the equipment by the cost of the repair. If the result is over 5,000, replace; if under, repair. It's a useful rule of thumb that should be modified by refrigerant generation, matched-system economics, and the efficiency gain from a replacement.
If the unit is over 8 years old and needs a meaningful repair, usually yes. R-410A is being phased down starting 2025, so refrigerant repair costs will continue rising. Newer equipment ships with R-454B or similar next-generation refrigerants.
On systems under 8 years old with a matching coil, yes. On systems 10+ years old it's usually a false economy — the mismatched coil drags efficiency down and shortens the new unit's life. Replace both at the same time when the system is older.
12–15 years is the typical KC lifespan with annual tune-ups. Without maintenance, that drops to 10–12. Houses near the airport (heavy dust loading) or with lots of cottonwood can see shorter outdoor-coil life.
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