Repair or replace your AC

Step one: how old is it?

This Old House gives 12 to 15 years as a normal service life for home cooling equipment, and the DOE's Energy Saver guide says replacement is worth considering once a heat pump or central AC passes 10. In Columbia a heat pump runs through the winter as well as the summer, so it piles up hours faster than a cooling-only unit bought the same year.

The year of manufacture is usually hidden in the serial number on the condenser's data plate. Text a photo of the plate along with your request and the technician can decode it.

Step two: how big is the repair?

Repair	Fixr 2026 range	If the unit is old
Capacitor	$100 to $400	Fix it
Thermostat	$150 to $500	Fix it
Leak repair	$200 to $1,500	Depends where it leaks
Evaporator coil	$400 to $2,700	Price a replacement first
Compressor	$600 to $3,000	Price a replacement first

To fold both steps into one number, use the $5,000 rule: age in years times the repair price. Above $5,000, get a replacement price.

Things that push the decision one way

• History. A third straight summer with a service call is a pattern.
• Refrigerant. The EPA says existing R-410A equipment can keep being repaired with R-410A parts. Units still on R-22 are costly to recharge. The refrigerant change.
• Comfort. A house that stays clammy while the system runs, or a bedroom that never cools, may be a sizing or duct issue no repair will fix.
• Efficiency floor. In Missouri a new split AC must rate at least 13.4 SEER2, and a split heat pump 14.3 SEER2.
• Money back. City of Columbia Utilities pays $800 to $1,200 on a qualifying replacement. The federal 25C credit expired at the end of 2025.

My own rule

Younger than 10: repair nearly anything that isn't a compressor. Older than 15: no new compressor or coil. I would replace it in April or October, when installers have openings, rather than wait for it to quit in the second week of a July heat wave.