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HVAC Repair vs Replace: The 50% Rule
The math
Repairs run $150–$600, partial parts (capacitor, contactor) $200–$600, compressor or coil $1,200–$2,500, full replacement $5,000–$9,000 for a typical 1,800 sq ft home. Size your case in the HVAC Cost Estimator.
Repair or replace rule
Replace when: system is 12+ years old, repair exceeds 50% of replacement, SEER under 13, or R-22 refrigerant is involved (phased out, brutally expensive). Repair when: under 8 years, first breakdown, and the fix is under $500.
Worked example: dead capacitor
The most common no-cool call: $15 part, $150–$300 installed, done in an hour. Compare: compressor failure on a 14-year-old R-22 unit at $2,200 — replace the system instead. Knowing which failure you have saves thousands before anyone arrives.
Getting quotes right
Demand Manual J load calculation — rule-of-thumb sizing oversizes equipment, short-cycles it, and breeds humidity. Three quotes should list SEER2, furnace AFUE, lineset replacement, permit, and thermostat. Summer emergency premiums run 25–50%.
Maintenance that prevents bills
Change filters every 1–3 months, hose condenser coils yearly, keep 2 ft clearance around the unit, and pour vinegar down the condensate line each spring. Annual $100 tune-ups catch capacitors before August failures.
Cost reality
Full 3-ton 16 SEER2 system installed: $6,000–$9,000; budget brands $1,500 less with shorter warranties. Energy savings of 20–40% over a 15-year unit repay upgrades in 5–8 years. More in home guides.
Limits
Online ranges cannot account for ductwork condition, electrical panel capacity, or permit costs — budget 15% contingency. Duct replacement can add $2,000–$5,000. Always verify license and refrigerant handling certification.
SEER math that matters
Each SEER2 point saves roughly 7% cooling energy. Jumping SEER 13 to 17 on a $200 summer bill saves ~$56 monthly in peak season — $300+ yearly in hot states. Size matters more than rating: an oversized 18 SEER short-cycles into humidity and mold, performing worse than a right-sized 15.
FAQ
How long do systems last? 12–17 years with maintenance; neglected ones die at 10. Second opinions? Free for quotes over $1,000 — compressor diagnoses deserve verification. Rebates? Federal credits plus utility rebates can cut $2,000+; check DSIRE before signing.
One last rule: photograph the data plate (model, serial, refrigerant type) and keep install permits plus Manual J paperwork in one folder. Warranty claims without registration die fast, and future buyers pay premiums for documented HVAC history with transferable labor terms.
Timing tip: replace systems in spring or fall when installers discount to fill schedules. Emergency August replacements cost 25–50% more for the same equipment installed by whoever is available fastest.