$5,000 HVAC Rule Calculator
Multiply repair cost by system age. If the result is over $5,000, replacement usually wins.
Tip: If the result is within 10% of $5,000, consider energy bills, repair history, warranty, and comfort before deciding.
The $5,000 AC and Furnace Rule is a simple formula to help homeowners decide whether to repair or replace their heating and cooling systems. If the repair cost multiplied by the system’s age is greater than $5,000, replacement is usually the smarter move. At Furnace.Guru, we make replacement affordable by finding you the lowest wholesale prices anywhere on furnaces — saving thousands compared to retail contractor quotes.
The $5,000 Rule
Few decisions in homeownership are as frustrating as choosing whether to repair or replace a failing HVAC system. You don’t want to waste money on repairs that won’t last, but you also don’t want to jump too quickly into a full replacement.
That’s where the $5,000 Rule comes in. This widely recognized guideline combines repair cost and system age into one calculation to give you a clear answer. And when the math points to replacement, Furnace.Guru finds you the lowest wholesale prices anywhere on furnaces — cutting out retail markups that contractors tack onto equipment.
Key Highlights
- Multiply repair cost × system age.
- If result is over $5,000, replacement is usually smarter.
- If result is under $5,000, a repair may make sense.
- Works for air conditioners and furnaces.
- Furnace.Guru helps make replacement affordable with wholesale prices.
The $5,000 AC Rule
Air conditioners generally last 10–15 years. Once they hit that range, repairs become more frequent and efficiency drops.
How To Use The Rule
- Get a repair estimate from a licensed technician.
- Multiply the cost of the repair by the system’s age in years.
- If the result is more than $5,000, replacement is usually best.
Examples
- A 10-year-old AC needs a $600 repair. 10 × $600 = $6,000. Replacement recommended.
- A 6-year-old AC with a $500 repair. 6 × $500 = $3,000. Repair is reasonable.
- A 13-year-old AC facing a $400 repair. 13 × $400 = $5,200. Borderline, replacement likely smarter.
This rule is not perfect, but it helps avoid spending thousands on a unit that’s near the end of its life.
The $5,000 Furnace Rule
Furnaces typically last longer than AC units. Gas furnaces run 15–20 years, while electric furnaces may last 20–30 years with proper care.
How To Apply It
- Multiply the repair cost by the furnace’s age.
- If the total is over $5,000, replacement is recommended.
Examples
- A 15-year-old gas furnace with a $500 blower repair = $7,500. Replacement recommended.
- A 7-year-old furnace with a $400 ignitor repair = $2,800. Repair is reasonable.
- A 20-year-old electric furnace with a $250 control board = $5,000. Replacement makes sense.
Because furnaces tend to last longer, the rule will often recommend repair for newer systems — but once you cross that 15- to 20-year mark, even smaller repairs often justify replacement.
Beyond The $5,000 Rule: Other Factors
While the formula is helpful, homeowners should also weigh:
Energy Efficiency
Older AC units may run at 10–12 SEER, while new systems exceed 15–20 SEER2. Older furnaces may operate at 70–80% efficiency, while modern gas furnaces hit 95%+. That’s a major difference in energy bills.
Warranty Coverage
If your system is still under warranty, repair may be more cost-effective. Once warranties expire, replacement becomes more appealing.
Comfort Issues
Uneven heating or cooling, poor airflow, or rooms that never stay comfortable are signs of a system that’s past its prime.
Refrigerant Phaseouts
AC units using R-22 refrigerant are especially expensive to repair because the refrigerant has been phased out.
Frequency Of Repairs
One repair is fine. Multiple repairs within two years indicate the system is breaking down across multiple components.
Cost Comparison: Repairs vs. Replacement
Typical Repair Costs
- AC capacitor: $150–$350
- AC coil replacement: $1,200–$2,500
- Compressor replacement: $2,000–$3,500
- Furnace ignitor: $200–$400
- Furnace blower motor: $500–$1,200
Replacement Costs (Wholesale)
- Gas furnaces: $1,200–$2,000 (Furnace.Guru)
- Electric furnaces: $1,100–$1,800 (Furnace.Guru)
- Central AC systems: typically $3,500–$5,500 (when available wholesale)
- Heat pumps: $3,800–$6,000 (when available wholesale)
By comparison, retail contractor quotes often double these numbers, adding $4,000–$7,000 in markup and labor. Buying wholesale through Furnace.Guru ensures you pay for the equipment only, at the lowest price possible.
Why Wholesale Wins
Most homeowners don’t realize how much markup gets built into retail HVAC quotes. The equipment itself may cost $2,000–$4,000, but by the time it’s bundled into a contractor’s proposal, it’s $8,000–$12,000.
Furnace.Guru finds you the lowest wholesale prices anywhere on furnaces. That means:
- No middleman markup.
- Full manufacturer warranty intact.
- Direct-to-door delivery.
You can then choose whether to hire a contractor for installation or, in some states, install it yourself.
The Calculator Advantage
To make this rule easy, Furnace.Guru offers a $5,000 Rule calculator:
- Enter your system type, age, and repair estimate.
- See instantly if the math favors repair or replacement.
- Get direct links to Furnace.Guru’s wholesale furnaces when replacement is recommended.
This tool turns an abstract formula into a clear decision point — with savings one click away.
Frequently Asked Questions
What is the $5,000 Rule in HVAC?
It’s a formula: repair cost × system age. If over $5,000, replacement is recommended.
Does it apply to both AC and furnaces?
Yes, the math works across both cooling and heating systems.
How long do furnaces and AC units last?
- AC: 10–15 years
- Gas furnaces: 15–20 years
- Electric furnaces: 20–30 years
Why choose wholesale over retail?
Wholesale avoids contractor markup, giving you the same brand-new equipment at a fraction of the price.
Does buying wholesale void the warranty?
No. Furnace.Guru furnaces come with full manufacturer warranties.
Final Thoughts
The $5,000 AC and Furnace Rule gives homeowners a clear, math-based way to know when to repair and when to replace. It removes the guesswork from one of the most stressful homeownership decisions.
And when replacement is the smarter move, Furnace.Guru finds you the lowest wholesale prices anywhere on furnaces. That’s the difference between paying $8,000–$12,000 for a contractor quote and paying $1,200–$2,000 for the same furnace, shipped directly to your door.
Use the $5,000 Rule, run the calculator, and shop wholesale with Furnace.Guru. It’s the smartest way to keep your home comfortable without overspending.