HVAC Repair or Replace Calculator

Multiply the system's age in years by the repair quote. Over $5,000 means replacement usually wins; under it, repair. A 12-year-old AC with a $750 quote scores $9,000 — replace. A 4-year-old system with the same quote scores $3,000 — repair, per the rule. HomeGuide and Fixr both publish this threshold, and it works because repair frequency and part failure climb steeply after year 10. Know its blind spot, though: the rule prices the repair while ignoring what's left of the system — a $4,900 score on a 15-year-old furnace is still a bad buy — which is why this calculator also runs the 50%-of-replacement check and the age-vs-service-life test before it commits to a verdict.

Usually not for a major component. Central AC lasts 12–15 years (HomeGuide), so a 12-year-old system is spending its last 0–3 summers; put the $9,000 rule score next to the $6,450–$8,710 replacement range and the repair is buying months, not years. Small fixes — a $250 capacitor, a contactor — can still be worth it to stretch one season while you shop quotes in the shoulder season.

A central AC swap runs $5,000–$12,000 installed (about $6,000 typical, Fixr); a ducted heat pump starts around $10,500; and replacing both furnace and AC together lands near $10,950 once permit and haul-away are included. Higher SEER2 tiers push the AC numbers up: roughly $4,500–$7,200 for a 16 SEER2 system and $6,000–$10,000 for 18 SEER2.

A compressor or evaporator coil on a system 10+ years old. Those parts run $1,800–$2,750 and $650–$2,400 installed — half the price of a new system for half of an old one. Also skip any repair that hinges on recharging an R-22 system: R-22 hasn't been manufactured in the US since 2020, so a leak fix means scarce refrigerant at premium prices, and the recharge buys you one season.

Savings = (1 − old SEER2 ÷ new SEER2) × your heating-and-cooling spend. Going from a 12-year-old system (~12.4 SEER2-equivalent) to 16 SEER2 saves ~22% — about $410/yr on a $150/mo bill — so the ~$1,200 premium over a baseline unit pays back in about 3 years at this bill level: faster where the cooling season is long, 5–10 years where bills run small. Jumping to 18 SEER2 saves ~31% but takes ~6 years to pay back its bigger premium; it's worth it mainly in long-cooling-season climates.

No federal one anymore: the 25C credit (30% of cost, up to $600 for central AC and $2,000 for heat pumps) was terminated for equipment placed in service after December 31, 2025 by the July 2025 federal budget law, so 2026 installs don't qualify — push back on any bid that still 'factors in the tax credit.' State energy offices and utilities still run rebates in many markets, so check your utility's rebate portal or the DSIRE incentives database before signing, and keep the AHRI certificate and itemized invoice for whatever program you claim.

When all three are true: the system is under ~8 years old, the quote is under 25% of replacement cost, and the $5,000 rule scores under $2,500 — for example a $250 capacitor on a 5-year-old unit (score $1,250). Repairs in that pocket buy 10+ more years of a system whose warranty may even still cover the part.

It tilts late-model replacements, not the math for an old system. Residential ACs and heat pumps built for 2025 ship on R-454B — the refrigerant that succeeded R-410A under the EPA's HFC phasedown — and early-production units have carried transition surcharges, one reason 2026 replacement quotes spread wider than usual. It does not make repairing a working R-410A system a mistake: R-410A remains available for service, unlike R-22, which stopped US production in 2020 and is the reason the calculator's 20-year note pushes so hard toward replacement. The ducts question that used to live here still matters and is excluded from every figure on this page: new ductwork adds roughly $1,400–$6,000 (Fixr), so price it with the ductwork calculator before you fold it into this decision.