The most expensive part to replace on an AC unit is the compressor, costing $1,200 to $2,800 installed for a residential system in Los Angeles. Compressors are expensive because they're precision-machined, sealed, and matched to a specific refrigerant, meaning the replacement must be identical in tonnage, refrigerant type, and electrical specs. The part alone runs $600 to $1,800, and the labor to recover refrigerant, swap the unit, pull a vacuum, and recharge adds several hundred more. Before approving a new compressor, always check your manufacturer warranty: most residential compressors carry a 10-year parts warranty, which can eliminate the part cost entirely and leave you paying only labor and refrigerant. If your unit is out of warranty and 10+ years old, full system replacement often costs only 40–60% more and qualifies for LADWP rebates up to $5,500. Call (818) 660-1062 for quotes.
