Age > 15 years — Expect diminishing returns on any single repair. Start pricing replacement in parallel, especially if a second failure in the last 24 months.
Repair cost > 50% of replacement — A $2,500 repair on an $8,000 system rarely pencils. Run the 5-year math: repair cost + likely follow-on failures vs new-system financing.
Uses obsolete refrigerant (R-22) — R-22 is phased out; refills are both expensive and short-lived. Replacement is almost always the right call.
Failed a major component (compressor, heat exchanger) — These are “the system”. A compressor on a 12-year-old condenser is a replacement signal, not a repair.
Typical repair cost range
O Fallon repair range$698 – $7,109per repair visit
Derived from local HVAC benchmarks in O Fallon. Most repair tickets fall well below full-system pricing — expect simple swaps (capacitor, ignitor, thermostat) at the low end and major component replacements (blower motor, control board, compressor) at the high end.
Estimate your O Fallon repair
Pick the repair type and your system's age for a ballpark range. Real quotes vary by part availability and diagnosis — use this as a sanity check before approving work.
How long does a typical HVAC repair take in O Fallon?
Most diagnoses take 30–60 minutes on site. Small repairs (capacitor swap, thermostat, ignitor) finish the same visit. Parts-on-order repairs can push the job 1–5 business days depending on supplier stock.
Do repairs come with a warranty?
Labor warranties of 30–90 days are common; parts usually carry the manufacturer's warranty (1–10 years). Always get the warranty terms in writing on the invoice before the tech leaves.
How do I avoid common repair scams?
Red flags: no written estimate before work starts, refrigerant refill with no leak search, blanket recommendation to replace without an inspection, or very high "after-hours" pricing on a non-emergency call. Two written quotes for any repair over $600 is the fastest sanity check.
When should I replace instead of repair?
When the repair estimate exceeds 50% of a new system, or the unit is past 15 years, or it uses obsolete refrigerant (R-22), replacement usually wins the 5-year math. Otherwise repair is almost always the better call.
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