The $5,000 AC rule, explained

Three worked examples

System age	Repair quote	Age x cost	Rule says
6 years	$300 capacitor	$1,800	Repair
12 years	$450 contactor	$5,400	Price a replacement
14 years	$2,200 compressor	$30,800	Replace

These are worked examples, not quotes. The repair amounts sit inside the national ranges published by Fixr and This Old House.

Where it falls short

The rule pushes you toward replacement for small repairs on older systems. The 12 year old system above crosses the line over a $450 part. A cheap repair on a system that otherwise runs well is often still the right call, as long as you start planning the replacement. Use the rule to decide whether to get a replacement price, not to decide what to buy.

It also ignores the things that matter in Mesa: whether the system keeps the house cool through a summer with 36.5 days a year at 110°F or more at Sky Harbor, whether the ducts leak into a hot attic, and whether you are paying for a repair every year.

A better version for Mesa

1. Run the $5,000 test.
2. If it fails, ask for a replacement quote alongside the repair quote.
3. Compare the repair to the replacement price minus any current SRP rebate. The federal 25C credit is gone for 2026 installs.
4. Think about timing. Replacing in March is easier and calmer than in a July breakdown.

The full repair or replace guide.