The $5,000 AC rule, explained
Take the age of the unit in years and multiply by the repair price. Past $5,000, get a quote on a new system. This Old House describes the rule that way, and it is a shortcut for deciding what to price, not an industry standard.
Running the numbers
| Age | Quoted repair | Product | Verdict |
|---|---|---|---|
| 6 | $300, capacitor | $1,800 | Fix it |
| 12 | $450, contactor | $5,400 | Get a replacement price |
| 14 | $2,200, compressor | $30,800 | Replace |
The dollar amounts are illustrations chosen to sit inside the Fixr and This Old House national ranges. They are not quotes.
The blind spots
The math leans toward replacement even for small fixes on older equipment. That 12 year old unit with a $450 contactor trips the threshold, yet if the rest of the system runs well, a cheap repair now plus a planned replacement later is often the sensible path. Treat a result over $5,000 as a reason to ask for a second number, not as an order to buy.
It also misses things a Columbia owner cares about. Does the system dry the house in a wet July, or only cool it? Is it a heat pump that also carries you through January? Has it needed a visit every summer?
An adjusted version for Boone County
- Do the multiplication.
- If it comes out over $5,000, ask for a replacement bid along with the repair bid.
- Subtract any rebate from the replacement price before comparing. City of Columbia Utilities pays $800 to $1,200 on a qualifying unit. Rebate rules.
- Think about the calendar. Installers have more room in April and October than during a July failure, and the utility gives you six months from installation to file for the rebate.
What Boone County homeowners ask us
How does the $5,000 AC rule work?
Multiply the unit's age in years by the repair price. This Old House suggests that a product over $5,000 means replacement may make more sense than repair. It is a shortcut, not a standard.
Can I use the $5,000 rule on a heat pump?
As a first pass, yes. Keep in mind that a heat pump runs summer and winter, so it wears faster than a cooling-only unit of the same age.