This is the question we get asked more than any other, and the honest answer is that it depends on three things: how old the system is, what the repair costs relative to a replacement, and how reliable the unit has been up to now. Here's how we walk customers through it.
Start with age. A well-maintained central air conditioner lasts about 12 to 17 years in our climate. Under 10 years, repair is almost always the right call — the system has plenty of life left and parts are usually still available. Over 15 years, you're on borrowed time, and putting a large repair into it often means paying twice. Between 10 and 15 is the genuine judgment zone.
Then do the repair-cost math. A useful rule of thumb: if the repair costs more than about a third of what a replacement would cost, replacement is usually the better value. Multiply the repair cost by the unit's age — if that number is bigger than the cost of a new system, replace it. It's a rough guide, not a law, but it tracks well with what actually makes financial sense.
Watch out for the expensive failures. Some repairs are cheap and worth doing on almost any system — capacitors, contactors, fan motors. Others are major: a failed compressor or a refrigerant leak in the evaporator coil can run half the price of a new system. On an older unit, those two are usually the point where replacement wins.
The R-22 problem. If your system is old enough to run on R-22 refrigerant, that matters a lot. R-22 was phased out and is no longer produced, so what remains is reclaimed and expensive. A leak in an R-22 system can cost a startling amount just to recharge — and it will leak again. If you have an R-22 unit with a refrigerant problem, replacement is nearly always the right answer.
Factor in your energy bills. An air conditioner from the early 2000s might be running at a SEER rating around 10. Current minimum-efficiency units are meaningfully better, and high-efficiency models better still. If your summer electric bills have been climbing and the system runs constantly on hot days, some of that repair money is going to come back to you as lower bills with a new unit.
Consider how often it's been breaking. Two service calls in one season on the same system is a pattern, not bad luck. Components tend to age out together, so when one thing goes on an old unit, others usually follow within a year or two.
What we'll do. When you call us for an AC that's quit, we diagnose the actual fault, tell you what the repair costs, and — if the system is old enough that it's a real question — price a replacement alongside it. Then you decide. We don't push new systems onto units that have good years left in them, and we'll say so plainly when a repair is the smart move.
PMV Heating and Cooling installs and repairs air conditioners across St. Charles, Naperville, Wheaton, Downers Grove, and the surrounding suburbs. Call (630) 415-8030 for a free replacement estimate.