The trade's shortcut is the age times cost rule: multiply the repair quote by the equipment's age. Under roughly 5,000, repair is usually sound. Over it, replacement usually wins. A $300 sensor repair on a 12 year old furnace (3,600) is a repair. A $1,500 blower and board on a 17 year old system (25,500) is money into a system whose other parts share its birthday.
Use the tract arithmetic. Mission Viejo systems were installed in waves, so your neighbors' experience is real data: if the street's same age systems are failing, yours is not special. Multiply the system's age by the repair quote; past the published 5,000 threshold, replacement is usually the better money. Then add the duct question, because replacing equipment on leaking 1970s ducts repeats the original mistake at modern prices. The written proposal should show both numbers, equipment and distribution, separately.
Three facts adjust the arithmetic. Refrigerant: older cooling systems use refrigerants that now cost enough to make a major cooling repair a replacement argument by itself. Ducts: a replacement on failed ducts buys a new machine with the old complaint. History: a first major repair at 14 years is a different bet from a third at 14 years.
The output of a good visit is both prices in writing, with the duct findings attached. Companies earn the replacement by showing the repair price honestly first. If you are only shown one number, you were not given a decision; you were given a direction.
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