Should I Repair or Replace My AC in Arizona?
A decision framework for Phoenix homeowners — from a contractor who won't push replacement unless it makes sense.
The Short Answer
Use the 5000 Rule: multiply the repair cost by the system age in years. If the result is over $5,000, lean toward replacement. Under $5,000, lean toward repair. Adjust for R-22 refrigerant systems (almost always replace) and units over 15 years old.
The 5000 Rule for Phoenix AC Decisions
Repair Cost Ă— System Age (years) = Decision Number
If Decision Number > $5,000 → lean toward replacement
If Decision Number < $5,000 → lean toward repair
Always Lean Toward Replacement When...
The Financial Case for Replacement in Phoenix
A 10-year-old AC in Phoenix might have a SEER rating of 10–13. A modern 18 SEER replacement can reduce cooling costs by 30–40%. In Phoenix where AC accounts for 50–65% of summer electric bills, this matters more than in most cities.
Example: Phoenix summer electricity savings
Old 12 SEER system: ~$350/month June–September = $1,400/summer
New 18 SEER system: ~$220/month June–September = $880/summer
Savings: ~$520/summer → new system pays back in ~10 years on efficiency alone