The Rule of 5000: Should You Repair or Replace Your AC?

Your AC just quit again. The tech is standing in your kitchen with a repair estimate, and you're doing the math in your head: is this worth fixing, or is it time to just replace the thing?

There's a simple formula Tucson homeowners can use to cut through that decision. It won't replace a real inspection, but it'll tell you which direction to lean before you spend another dollar.

What is the Rule of 5000?

Multiply the age of your AC (in years) by the cost of the repair it needs. If the number comes out over 5,000, treat that as a prompt to compare options in writing—not as proof that replacement is the better value. Under 5,000 does not mean repair is the better value either. The formula leaves out the replacement price, warranty coverage, equipment condition, and whether the repair solves the problem. For the replacement side of that comparison, see what a new AC costs in Tucson.

Two illustrative examples — not a quote, just the math:

• For example, a 6-year-old system with a $500 capacitor-and-contactor repair: 6 × 500 = 3,000. Under 5,000 — the formula doesn't flag replacement, but the diagnosis still decides.
• For example, an 8-year-old system with a $900 blower-motor repair: 8 × 900 = 7,200. Over 5,000 — a prompt to price repair and replacement side by side in writing; the on-site inspection is what actually decides.

Those numbers are illustrative, not from a real job. For a documented repair (not a documented repair-versus-replace decision), see how we replaced a failed indoor blower motor in Tucson or replaced an evaporator coil in Marana.

The formula isn't magic. It's a rough screening rule — a fast way to weigh today's repair bill against the system's age, instead of deciding in the moment with a tech standing in your doorway. It doesn't measure how much life is left in the unit, what it costs to run, or its repair history — those take a real look at the equipment, not just this formula.

Why the math matters in Tucson heat

A well-maintained AC typically runs 10–15 years before the math starts working against it. Around that age, repairs tend to get more frequent and more expensive.

Tucson's cooling season runs long — March into October — so a system that's already inefficient can cost more to run here than the same unit would in a milder climate. Age alone doesn't tell you how much efficiency a system has lost; its condition and maintenance matter. What it costs to run also depends on usage and current TEP rates. A well-maintained system can hold up better than its age alone suggests.

Where refrigerant fits into the math

If your system still uses R-22, that refrigerant hasn't been produced in the U.S. since 2020. Existing R-22 systems can still be serviced using remaining stock or refrigerant that's been recovered and reclaimed, but supply is limited and a recharge can run high — ask for the actual repair estimate rather than assuming the cost.

R-410A, the refrigerant in most systems installed over the last 10–15 years, is now in its own phase-down. Starting in 2025, newly manufactured residential AC and heat-pump equipment began transitioning to lower-GWP refrigerants such as the A2Ls R-454B and R-32. That does not mean an existing R-410A system needs to be replaced — it doesn't, and nothing about the transition forces the issue. If a repair estimate includes refrigerant, it's worth asking what your system uses and whether parts for it are getting harder to find. That's information for the math — not a reason to replace early.

Other signs it's time to replace, not repair

The formula is a starting point. These push the decision toward replacement even when the math is close:

• R-22 refrigerant. Supply is limited to what's on hand or reclaimed, and a recharge can be expensive — get the actual estimate (see above).
• Uneven cooling or hot spots. If parts of the house never cool right no matter what you do, the system may be undersized or failing — but ducts, airflow, and sizing get checked first before anyone calls it a replacement sign.
• Repairs every season. Repeated calls deserve a review of the repair history. Ask whether they involve one unresolved fault or separate component failures, and compare the documented condition and written options before deciding.
• Rising utility bills with no other explanation. Worth a look if the TEP bill is climbing without an obvious cause during cooling season.

None of these alone means "replace it today." Together with a repair bill that's climbing, they're worth taking seriously.

What we actually do before we tell you which way to go

We don't guess, and we don't quote a replacement off a phone call. When one of our techs is at your home for an AC repair, they test the system — not eyeball it — before giving you a number. If a repair still makes sense, we'll say so. If the math and the condition of the system both point to AC replacement, we'll walk you through what that looks like and put the price in writing before any work starts.

Every repair we do carries a written 1-year materials-and-labor warranty on repairs. (see the full warranty terms) And qualifying installations are backed by our written 1-year money-back guarantee — the full terms are on our guarantee page — so if the answer turns out to be replacement, you're not just trusting a sales pitch to be right.