A tech is in your basement saying "it's old, just replace it." Maybe, or maybe a $400 part buys you three good years. Enter your system's age and the repair you're facing, and this tool runs the honest cost-per-remaining-year math, cross-checks the famous rules of thumb, and gives you a verdict, with a confidence level and the exact questions to ask. If the answer is "repair it," it'll say so.
Rough numbers are fine: the result updates as you type.
No replacement quote yet? Leave it blank and we'll estimate from 2026 ranges (and say so. The verdict is sharper with a real number).
Leave blank if unsure. We model $0 (and flag it), so we never oversell efficiency you can't count on.
1 · Here's what we found
2 · What to actually do (the decision, not a sales pitch)
3 · Your next move
This tool tells you whether to replace. The next question is whether the quote you're handed is a fair price. Our free line-by-line autopsy reads it against real 2026 ranges, flags what's missing, and hands you the questions to ask. We'll carry over your system type so you don't re-enter it.
Check if your quote is fair →The cost-per-remaining-year math, the refrigerant questions, and the full checklist to run before any replacement, so you decide on the numbers, not the pressure. One email, no spam.
The tool isn't a black box. Here's exactly how it weighs the decision. The same honest framework a good contractor would walk you through.
Comparing a repair's sticker price to a new system's sticker price is apples to oranges. The frame that actually answers the question compares what each path costs per year of service you get:
Repair path = repair cost ÷ the realistic remaining years the repair buys on the old unit.
Replace path = new-system cost ÷ the new unit's expected lifespan, minus any annual energy savings.
These are famous quick gut-checks. The tool computes both and uses them to cross-check the cost-per-year verdict: agreement raises confidence; disagreement lowers it.
Multiply the unit's age by the repair cost. Over $5,000 leans replace (e.g., a 12-year-old AC × a $500 repair = $6,000). Many 2026 sources now put the practical line nearer $6,000–$7,000 given higher equipment costs and the R-410A phase-out, so we treat it as a flag, not a law.
If a single repair costs 50% or more of a new system's price, especially past mid-life, replacement usually wins. A $4,500 compressor on a system you could replace for $9,000 is a hard case for repair.
Half the decision is just knowing whether the repair in front of you is small or serious. Typical installed ranges:
| Repair | Typical range | Notes |
|---|---|---|
| Capacitor | $150–$400 | Most common, cheapest: rarely a reason to replace |
| Refrigerant recharge | $250–$1,000 | Rising fast for R-410A (see below) |
| Blower motor | $300–$2,000 | High end for variable-speed/ECM |
| Control board | $400–$1,200 | Communicating boards at the high end |
| Heat exchanger | $1,250–$3,000 | Safety-critical (CO); often a replace signal on old units |
| Evaporator / condenser coil | $1,900–$3,000 | Often a tipping point |
| Compressor | $1,200–$3,500 | Most expensive; frequently crosses the replace threshold |
Sources: HomeAdvisor, Angi, This Old House, Trane, CHT Refrigeration, PowerPro (2025–2026 installed estimates). Ranges vary by region. Verify locally.
If your system runs on R-410A (most from ~2010–2024) and it's leaking, the economics have shifted hard. R-410A is being phased out under the EPA's AIM Act; existing systems can still be serviced, but the refrigerant is getting scarce and expensive:
| R-410A cost | 2024 | Early 2026 |
|---|---|---|
| Wholesale per lb | $8–$12 | $15–$45 |
| Typical 3-ton recharge | $400–$700 | $500–$1,000+ |
New 2026 equipment uses A2L refrigerant (R-454B or R-32), which adds roughly an 8–15% premium over old R-410A gear. You generally can't mix refrigerants. A new A2L system needs matched indoor + outdoor units, so a coil or compressor failure on an R-410A system pushes toward a full matched replacement rather than a partial repair. Pre-2025 R-410A units can still be installed from existing stock in most states, but some (e.g., New York) are stricter. Verify locally.
Multiply the unit's age in years by the repair cost; if it's over $5,000, lean toward replacing (e.g., a 12-year-old AC × a $500 repair = $6,000). It's a quick gut-check, not a law. Many sources now put the practical line at $6,000–$7,000. We use it as one cross-check against the cost-per-remaining-year math, not as the verdict.
ACs and heat pumps hit diminishing returns after about 10–15 years; gas furnaces and boilers run 15–20 if the heat exchanger is intact (Energy Star suggests considering replacement past 15). Age is a backdrop, not a verdict. The tool combines it with the repair cost and the cost-per-remaining-year math.
Usually not as a long-term fix. R-410A is being phased out and its price has jumped (roughly $15–$45/lb wholesale in early 2026, up from $8–$12 in 2024), so a leaky system can rack up $2,000–$3,500 over five years. Check the leak box in the tool and it adds that burden to the repair side. Ask where the leak is and what fixing it costs, not just the price of another top-off.
It compares cost per year of service: the repair spread over the realistic remaining life it buys, versus a new system spread over its full lifespan minus any energy savings. It then cross-checks the $5,000 rule and the 50% rule, and reports a confidence level based on how well those signals agree. It's educational decision support, not a diagnosis.
Yes, and often. A cheap fix on a unit with real life left is a repair, full stop, and the tool says so plainly. It's a trust tool, not a sales funnel: it gives the non-commercial answer when that's the honest one.