Repair or replace

Should you repair or replace your AC? Three rules that decide it

When a repair quote lands, three rules of thumb cut through the guesswork — the $5,000 rule, the 50% rule, and the 3-minute rule. Here's what each one actually means, where it holds up, and where a New Braunfels homeowner should look past it.

$5,000 rule

System age × repair cost. Over $5,000 leans replace.

Use it for A costly repair on an aging system

50% rule

Replace if one repair tops 50% of a new system, or the unit is 12–15+ years old.

Use it for Judging an old or worn system

3-minute rule

Wait 3–5 minutes before restarting so the compressor can equalize pressure.

Use it for Resetting an AC that stopped cooling

Rule one

What is the $5,000 rule for HVAC?

Multiply your system's age by the repair cost; if the result tops $5,000, replacement is usually the better value. A 10-year-old unit facing a $600 repair scores 6,000 — lean replace. It's a fast gut-check, not gospel: the threshold has crept up with equipment inflation (it used to be the $3,000, then $4,000 rule), so weigh it alongside the system's overall condition and warranty status.

Rule two

What is the 50% rule?

Replace rather than repair when a single repair exceeds 50% of a new system's price, or when the unit is already 12–15+ years old. Age is its own trigger here. In our climate the DOE pegs average central-AC life at about 18 years, so a big repair on a system past the 12–15 year mark often means paying to extend something already near the end of its run.

Rule three

What is the 3-minute rule?

After the system shuts off or trips, wait 3 to 5 minutes before restarting it. The compressor The outdoor unit that releases heat pulled from inside your home. Full definition needs time to equalize internal pressure; restarting too soon can trip the breaker and, repeated over time, wear the compressor out early. If your AC just stopped cooling, this is also the safe pause before you start the troubleshooting checks.

The 2026 wrinkle

How does the R-410A ban change the math?

One Texas-specific factor tilts older systems toward replacement: as of January 1, 2025, new residential systems can no longer be manufactured with R-410A refrigerant The refrigerant in most pre-2025 systems. Manufacturing of new R-410A systems was banned in 2025, so parts will get scarcer. Full definition . Existing R-410A systems are still legal to service, but the refrigerant and parts grow scarcer and pricier each year, so a large repair on an R-410A unit buys less runway than it used to. U.S. EPA (HFC phasedown)

Common questions

Repair-or-replace FAQs

What is the $5,000 rule for HVAC?
Multiply your system’s age in years by the estimated repair cost. If the result is over $5,000, replacement is usually the better value; under $5,000, repair. A 10-year-old unit needing a $600 repair scores 6,000 — lean replace. Note the threshold has drifted up with inflation (it was the $3,000, then $4,000 rule), so treat it as a guide alongside the system’s age and condition. Source: Carrier.
What is the 50% rule for replacing an air conditioner?
Replace rather than repair if a single repair costs more than 50% of a new system’s price, or if the unit is already 12–15+ years old. Age is an independent trigger: even a cheap repair on a 15-year-old system can be money better put toward replacement, since the rest of the unit is near the end of its life. Source: leads4build.
How long does a central AC system last in Texas?
The U.S. Department of Energy uses an average life of about 18 years for a residential central AC in the hot-humid South, including Texas — shorter than the 24–25 years used for cooler regions, because our long cooling season works the system harder. Past 12–15 years, factor that remaining life into any big repair. Source: U.S. DOE.
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