Repair it or replace it?
The test contractors and homeowners both use, run on your numbers, with the refrigerant question folded in. Takes about fifteen seconds.
Check the data plate on the unit. Most manufacturers encode the build date in the serial number.
Replacement is very likely the better spend.
The age-times-cost test is a starting point that contractors and homeowners both use. It is not a diagnosis. A cracked heat exchanger ends the discussion regardless of the number, and so does a compressor failure on equipment past its service life.
Get competing quotes freeHow the test works
Multiply the age of the equipment in years by the cost of the repair being quoted. If the result clears roughly $5,000, replacement generally makes better financial sense. The logic is simple: money spent on equipment with little remaining life buys you very little time, while the same money put toward new equipment buys you fifteen years.
A $350 repair on a five-year-old furnace comes to $1,750. Easy call, fix it. That same $350 repair on a twenty-year-old furnace comes to $7,000, and you are spending real money on something that may fail again next winter.
Where the test breaks down
- A cracked heat exchanger is a combustion safety issue, not a financial one. It ends the conversation regardless of what the arithmetic says.
- A failed compressor on equipment past its service life is almost always a replacement, because the repair approaches the cost of a new condenser.
- Refrigerant type can override the number entirely. A leak on an R-22 system often costs more in refrigerant than the rest of the repair combined.
- How long you are staying. If you are selling in eighteen months, the calculus is different and a repair may be the right answer even at a bad ratio.
Finding your system’s age
Look for the data plate on the unit, usually a metal or foil label on the side of the furnace cabinet or the outdoor condenser. Most manufacturers encode the manufacture date in the serial number, and many print it plainly. If the house has had one owner and you have the paperwork, the install date is more accurate than the build date.
Before you accept any replacement quote
- Ask whether they ran a Manual J load calculation or just matched existing tonnage
- Ask what refrigerant the new equipment uses
- Ask for the SEER2 and, on a heat pump, the HSPF2 rating in writing
- Ask whether the quote includes any ductwork correction or just equipment swap
- Get the labor warranty term separately from the manufacturer parts warranty