Repair or replace? The age rule, the 50 percent rule and the R-22 and R-410A math for a Valley home

Three rules of thumb decide most repair-or-replace calls on a Valley AC: replace once the system reaches about 10 to 12 years, replace when the repair costs more than half of a new system, and replace when the system's age times the repair bill tops $5,000. Run them against published Valley prices and they often disagree: a $1,400 to $3,000 compressor is only 11 to 33 percent of a typical $9,000 to $13,000 split-system replacement, yet on a 12-year-old system it blows far past the $5,000 rule. The refrigerant on the nameplate usually breaks the tie, because R-22 now runs $100 to $250 a pound installed and R-410A $40 to $90.

We make this call on AC repair visits across Glendale and the West Valley, and the honest answer is often the repair. Our Glendale replacement story shows one 15-year-old system where the compressor was failing and replacement won. The rules and the math behind calls like that let you check a recommendation before you sign for a replacement.

What are the three rules of thumb for repair or replace?

Each is a starting point, and each misses something the others catch:

• The age rule: at about 10 to 12 years, lean toward replacing. SRP lists "your equipment is 10-plus years old" first among its signs that it is time to upgrade, and EPA suggests considering a new system for equipment over 10 years old.
• The 50 percent rule: if the repair costs more than half the price of a new system, replace. Our Glendale story sets the bar lower. If the repair runs more than about 30 to 50 percent of a new system, replacement usually wins, particularly on an older unit.
• The $5,000 rule: multiply the system's age in years by the repair cost, and above $5,000, replace. The $5,000 line has not moved while replacement prices have, so it now condemns almost any mid-size repair past year five. Use it as a tiebreaker.

The age rule ignores how cheap a repair might be, and the 50 percent rule ignores age. The $5,000 rule leaves out refrigerant and warranty.

Why does a Valley AC wear out faster than the rules assume?

Runtime. Phoenix Sky Harbor averages 111 days a year at 100F or hotter (1991 to 2020 normals), and 2024 brought 143, including a record 70 days at 110F or hotter. SRP's own savings math assumes 2,141 cooling hours a year for a Valley system. Every one of those hours is compressor and fan-motor time, with monsoon dust packing the condenser coil and summer storms knocking the power around.

A 12-year-old system here has worked through a dozen of those summers, which is why the systems we replace are most often around 10 to 12 years old and why the age rule deserves more weight in the Valley than it gets in a national guide.

What does the refrigerant on the nameplate do to the math?

It can more than double the refrigerant bill on a leak repair. EPA notes that most units carry a nameplate naming the refrigerant, so start there.

R-22: U.S. production and import ended January 1, 2020. You can keep using and servicing an R-22 system, but its refrigerant now comes from recovered and reclaimed supply or inventory made before 2020, and there is no drop-in replacement. Since January 1, 2010, new R-22 could only be made or imported for equipment built before that date, so an R-22 nameplate in 2026 almost always means a system 16 or more years old. Trane's 2025 pricing guide puts R-22 at $100 to $250 a pound installed. At 2 to 4 pounds per ton, a full charge on a 3-ton system is 6 to 12 pounds, or $600 to $3,000 in refrigerant alone.

R-410A: new R-410A systems were phased out for manufacture as of January 1, 2025. The refrigerant is still available for service at $40 to $90 a pound installed in the same guide, or $240 to $1,080 for a full 3-ton charge. Trane expects that price to rise as supplies dwindle.

EPA's advice for any leaking system is to find and fix the leak rather than top it off each summer. That is where the money goes: the leak search, the repair, then the charge. The 2 to 4 pounds per ton is a rule of thumb. The nameplate shows the factory charge, and a long line set adds to it. The usual Valley leak spots are pinhole corrosion in older copper evaporator coils, Schrader valve cores, and lines rubbing on the pad or the stucco.

Can you replace just the outdoor unit on an R-410A system?

Sometimes, and it is often the cheapest fix for a 6 to 9 year old system. EPA allows a failed R-410A component, a condensing unit included, to be replaced with a similar R-410A part. The old indoor coil stays, the pair must still be an AHRI-listed match that meets Arizona's minimums, and SRP pays nothing, because Cool Cash requires both halves of a split to be replaced (as of October 2026). EPA also lets R-22 owners replace a condensing unit, but the new one must meet today's regional efficiency standards.

What does the compressor warranty cover, and what is left to pay?

Usually the part and not much else. Trane's residential limited warranty covers "parts (but not labor)": five years on the compressor, outdoor coil and parts if the unit was never registered, and ten years (twelve on the compressor of certain series) if it was registered online within 60 days of installation. Refrigerant is excluded, and a compressor replacement requires a new liquid-line filter drier. Goodman's certificate for its GLXS models runs five years unregistered and ten years on all parts if registered within 60 days, while the original registered owner lives in the home. Select Goodman models add a 10-year unit replacement.

Arizona is not on Trane's or Goodman's lists of states where registration is waived (Trane's certificate names Florida only), so a missed registration usually means the shorter term. A compressor that fails at year eight on a registered unit can mean a free part, with the labor, the drier, the refrigerant and the diagnostic still on you. Find the registration confirmation from the original install before you price the repair. It is the first paper Alex asks for on a compressor call.

Before any of that, confirm the compressor is dead. A tech condemns one only after checking the run capacitor against its microfarad rating, the contactor, the winding resistance and a short to ground, because plenty of July "dead compressors" are a failed capacitor or an internal overload tripped by a hot, dirty condenser coil. A real swap means recovering the charge, replacing the compressor and the liquid-line filter drier, adding a suction-line drier after a burnout (the oil gets an acid test), brazing under nitrogen, pressure-testing, pulling a vacuum to about 500 microns and weighing in a full charge. That is why labor and refrigerant are most of the bill even when the part is free.

What do repair and replacement cost in the Valley, side by side?

Most single repairs run a few hundred dollars, a compressor runs $1,400 to $3,000, and a complete split replacement lands around $9,000 to $13,000 installed, with the full range running roughly $6,500 to $18,000+.

How do the rules play out on three common Valley calls?

On these numbers, a small repair on a young system still wins, a compressor on a 12-year-old system leans toward replacement, and a leaking 16-year-old R-22 system should be replaced. Each case is a worked example built only from the prices in the table above.

Case A passes the percentage test easily, but at $800 and 8 years it fails the $5,000 rule ($6,400). That is the dated rule talking, and the repair still wins. Case B passes the 50 percent test but fails the age and $5,000 rules, and at the top of its range it crosses our 30 percent bar. The refrigerant and the summer calendar decide it. Case C still squeaks under 50 percent, but at 16 years on R-22 it fails the age and $5,000 rules by a wide margin.

When does it make sense to repair now and replace in the fall?

Often, in a Valley July. If a repair of a few hundred dollars gets a 13-year-old system through the summer, buying the replacement in October or November leaves time for a load calculation, two or three quotes and the rebate paperwork. SRP's Cool Cash requires installation before April 30, 2027 and a filing within six months, and a single-stage system needs a Manual J with the application (as of October 2026). APS no longer lists AC rebates on aps.com (checked October 22, 2026). Winter visitors in Sun City and Sun City West, here roughly November to April, have the same window.

The opposite holds when the repair itself is big: $3,000 into a compressor on a system you plan to replace in the fall buys a few months of cooling. The NWS average first 100-degree day at Sky Harbor is May 2, so the calm window for a planned replacement closes in late April. Our finished replacements are in the project gallery.

Text us a photo of your condenser's nameplate and the repair quote you were given, and we will tell you which way the numbers point, or call 480-853-6627 for a free estimate anywhere in the Valley. Request a free estimate online if you would rather write.