AC Replacement in Fort Mill, SC

When replacement makes sense

• The compressor or evaporator coil has failed, or the system needs repeated refrigerant top-ups.
• Repairs are getting frequent and the system is near the end of its service life.
• The system uses R-410A and has a leak. New residential systems have used lower-GWP refrigerants since Jan 1, 2025, so parts and refrigerant for the old system are a shrinking market (details in the cost guide).
• The house has grown, cooling is uneven, or bills keep climbing with no change in use.

What a good replacement job includes

• A load calculation (ACCA Manual J) to size the new system, not a copy of the old tonnage.
• Matched indoor and outdoor units with an AHRI certificate, meeting the Southeast minimum of 14.3 SEER2 for systems under 45,000 BTU/h (13.8 SEER2 at 45,000 and above).
• Refrigerant lines flushed or replaced, a new pad, disconnect, drain line and thermostat as needed, and the ductwork inspected for leaks and sizing.
• A permit and inspection where required, and the manufacturer's warranty registered in your name.

Permits in Fort Mill

York County Permit Services says a permit is required to install, alter or replace mechanical systems, and that all contractors must be licensed through SC LLR. The county issues permits for unincorporated addresses; if your home is inside town limits, the town's own building department handles it. Ask the installer who pulls the permit and who schedules the inspection, and get that in the quote (York County residential permits).

How to compare quotes

Get at least two written quotes that name the exact model numbers, SEER2 rating, refrigerant, what happens to the ductwork and the thermostat, permit handling and the labor warranty. The AC replacement cost guide walks through what drives the price and the national ranges published by the sources we checked.

Fort Mill notes

Fort Mill is in York County, SC, and the companies below are based there. For a repair instead of a replacement, see AC repair in Fort Mill. Ratings shown are Google's as of Oct 2026; we rank by rating, then review count, and never sell placement.