Quick things to check first
Before calling a pro, rule out the simple stuff: a thermostat set to the wrong mode, a tripped breaker, or a clogged air filter. A dirty filter chokes airflow and is the single most common reason a system underperforms — and it's free to fix.
If those are fine and the system still blows warm air or barely cools, it's time for a diagnostic.
Common causes and typical repair costs
Most no-cooling calls trace back to a handful of issues. Here's what they generally cost to fix in 2026.
- Dirty air filter or coils: ~$100 – $300 for cleaning (or free filter swap).
- Failed capacitor: ~$150 – $400 — a very common, quick fix.
- Bad contactor: ~$150 – $350.
- Low refrigerant / leak: ~$200 – $1,000+ depending on leak repair and recharge.
- Frozen evaporator coil: ~$100 – $400 (often airflow- or refrigerant-related).
- Failed compressor: ~$1,200 – $2,800+ — often a replace decision.
- Blower motor failure: ~$450 – $1,000.
Why is my AC running but blowing warm air?
Warm air with the system running usually points to low refrigerant (a leak), a frozen coil, a failing compressor, or a dirty condenser that can't reject heat. A technician will measure refrigerant pressures and temperatures to pinpoint it rather than guess — accurate diagnosis avoids paying for parts the system doesn't need.
Repair or replace?
A common guideline is the “$5,000 rule”: multiply the repair cost by the age of the unit; if the result tops $5,000, replacement usually makes more sense. A 12-year-old system facing a $1,500 compressor repair ($18,000) is a clear replace; a 4-year-old unit needing a $250 capacitor is an easy fix.
Systems on phased-down R-410A refrigerant, units past 12–15 years, and repeat breakdowns all tilt toward replacement.
Get a clear repair or replacement quote
Whether it's a quick capacitor or a full replacement, a clear itemized estimate beats a vague verbal number. Contractors using Fast Estimate diagnose on-site, snap a photo of the unit, and let AI draft repair or replacement line items — then hand over a branded, signable estimate on the spot.