Quick answer
- Past ~12 years + major repair → lean replace
- Repair cost over ~30–40% of replacement → lean replace
- Newer unit, minor fix → repair
- Always get the real numbers for both before deciding
When this applies
Use this when facing a big repair
The decision matters most when a quote includes a compressor, evaporator coil, or refrigerant leak repair on an aging system.
Your options
Repair
Best for newer systems (under ~10 years) with a contained problem. Lowest upfront cost, but throwing money at an old system risks repeating it next season.
Replace
Best for systems past ~12 years or facing major component failure. Higher upfront cost, but a modern high-SEER2 system lowers bills and resets reliability — and may qualify for SDG&E rebates and financing.
What to watch out for
Repeated band-aid repairs
Paying for repair after repair on a dying system usually costs more over two years than replacing would have.
Schedule service
Frequently asked questions
What's the rule of thumb for repair vs. replace?
Multiply the system's age by the repair cost. If that number exceeds roughly 5,000, replacement is usually the better value. We'll walk through your specific numbers.
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Reviewed by John Stevenson Plumbing, Heating & Air. Combines standard HVAC repair-vs-replace heuristics with local efficiency and rebate considerations. Last updated 2026-06-18.