Cost guide · 5 min read
Repair or replace: how to decide on an aging HVAC system.
A practical framework for the moment a technician quotes a repair on a system that is already past its prime.
Start with age, not the repair bill
Most residential systems are engineered for a service life measured in the low teens of years. Once a system passes that mark, individual repairs stop being investments and start being extensions.
Ask the technician for the manufacture date off the data plate rather than relying on the installation paperwork.
Weigh the repair against remaining life
A useful test: divide the repair cost by the number of years the system can reasonably be expected to keep running. Compare that figure to the annualized cost of a new system across its full warranty period.
If the repair involves the compressor or the heat exchanger, replacement usually wins that comparison outright.
Sizing is where a replacement goes wrong
An oversized system short-cycles, fails to dehumidify, and wears itself out early. Any contractor quoting a replacement should perform a load calculation rather than matching the tonnage of the old unit.
If a quote arrives without a load calculation, that is a reasonable thing to ask about before you sign.
A note on pricing figures
A full system replacement — furnace plus air conditioner — generally runs $5,500 to $14,000 installed, with heat pumps between $6,000 and $18,000 depending on tonnage and efficiency. Single-component repairs usually land between $200 and $1,500.
Ductwork modifications, electrical upgrades, and high-SEER equipment push the top of these ranges higher.