The compressor is the pump that circulates refrigerant and drives the entire cooling cycle — the most expensive single component in an air conditioner. When it fails, the system stops cooling entirely, and the repair decision is the biggest one a homeowner faces short of full replacement.
The first question is always warranty. Most compressors carry a manufacturer parts warranty of 5 to 12 years; if yours is still covered, you typically pay only labor — roughly $600 to $1,200. Out of warranty, a replacement runs about $1,800 to $2,800 installed, and more on larger systems. At that price, the common rule of thumb applies: if the repair exceeds about half the cost of a new system, replacing the whole unit is usually the better value — especially on an older R-410A system, since newer equipment uses different refrigerant.
The compressor is also where the worst overselling happens. Its failure symptoms — won't start, hums, trips the breaker — are identical to a dead capacitor or contactor that cost a fraction as much. A trustworthy shop confirms a true compressor failure with electrical and pressure testing and shows you the warranty status before quoting a replacement. 'Your compressor is shot' delivered without that diagnosis is the classic AC-repair upsell.