Repair or Replace HVAC Calculator: The $5,000 Rule and More

How the calculator scores your answers

Each answer adds weight to one side. No single rule decides the result.

The $5,000 rule. Multiply the system's age in years by the repair quote. A result over 5,000 leans toward replacement. Between 3,000 and 5,000 is a warning.
Repair as a share of replacement. A repair quote at 30% of a replacement quote is a warning. At 50% it leans toward replacement.
Age. ENERGY STAR suggests you consider replacing an AC or heat pump that is more than 10 years old, and a furnace or boiler that is more than 15 years old.
R-22 refrigerant. An AC that runs on R-22 leans toward replacement, because the refrigerant is no longer made or imported in the US.
Repair history. Two or more repairs in the past two years lean toward replacement.
A failed major component out of warranty. A compressor, coil or heat exchanger failure with no warranty leans toward replacement.
An active parts warranty. This leans toward repair, since the manufacturer pays for the part.

Where these rules come from

These are rules of thumb. None of them is an industry standard or a code requirement. The $5,000 rule circulates widely in the trade, and no standards body publishes it. The 30% and 50% thresholds are this site's own cut-offs. The age guidance comes from ENERGY STAR, which says to consider replacement at those ages. It does not say equipment fails at those ages.

For the reasoning behind each factor, read the guides on repairing or replacing an air conditioner and repairing or replacing a furnace.

What the calculator cannot tell you

The calculator only knows what you type in. It cannot see the condition of your equipment, your ducts or your home. A well-kept older system can be worth a modest repair. A younger system with a poor installation can be a money pit.

The fixed 5,000 figure also does not move with prices in your area, so a repair in a high-cost market trips it sooner. The quote comparison is only as good as the quotes. If you do not have a replacement quote yet, the guide to HVAC replacement cost explains what one should include.

The calculator does not diagnose anything. A licensed technician has to confirm what failed before any of these rules mean much.

Common questions

What is the $5,000 rule for HVAC?

It is a rule of thumb. You multiply the age of the system in years by the repair quote in dollars. If the result is more than 5,000, the rule says replacement deserves a serious look. It is a quick screen that ignores the condition of the equipment, local prices and warranty coverage, so use it alongside other signals.

Should I repair or replace my AC if it is still under warranty?

An active parts warranty usually favors repair, because the manufacturer covers the failed part and you pay labor and refrigerant. Check the warranty paperwork first. Coverage often depends on registration and on who did the installation, and labor is commonly a separate warranty from the installer.

Does the calculator work for furnaces and heat pumps too?

Yes. You pick the equipment type and the age rule changes to match. ENERGY STAR suggests considering replacement after 10 years for an AC or heat pump and after 15 years for a furnace or boiler. The refrigerant question only applies to AC units and heat pumps.

What if I only have a repair quote and no replacement quote?

The calculator still scores the other six signals. The repair-to-replacement comparison is skipped until you enter a replacement figure. Getting at least two written replacement quotes gives you a real number to compare against and makes the result more useful.

Sources